Data storage system with rapid restore capability

ABSTRACT

An improved information management system that implements a staging area or cache to temporarily store primary data in a native format before the primary data is converted into secondary copies in a secondary format is described herein. For example, the improved information management system can include various media agents that each include one or more high speed drives. When a client computing device provides primary data for conversion into secondary copies, the primary data can initially be stored in the native format in the high speed drive(s). If the client computing device then submits a request for the primary data, the media agent can simply retrieve the primary data from the high speed drive(s) and transmit the primary data to the client computing device. Because the primary data is already in the native format, no conversion operations are performed by the media agent, thereby reducing the restore delay.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

This application is a Continuation of U.S. Pat. App. 17/498,212 filed onOct. 11, 2021, which is a Continuation of U.S. Pat. App. 17/356,981filed on Jun. 24, 2021 (abandoned), which is a Continuation of U.S. Pat.App 17/202,078 filed on Mar. 15, 2021 (abandoned), which is aContinuation of U.S. Pat. App. 16/525,286 filed on Jul. 29, 2019(abandoned). Any and all applications for which a foreign or domesticpriority claim is identified in the Application Data Sheet, or anycorrection thereto, are hereby incorporated by reference into thisapplication under 37 CFR 1.57.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentand/or the patent disclosure as it appears in the United States Patentand Trademark Office patent file and/or records, but otherwise reservesall copyrights whatsoever.

BACKGROUND

Businesses recognize the commercial value of their data and seekreliable, cost-effective ways to protect the information stored on theircomputer networks while minimizing impact on productivity. A companymight back up critical computing systems such as databases, fileservers, web servers, virtual machines, and so on as part of a daily,weekly, or monthly maintenance schedule. The company may similarlyprotect computing systems used by its employees, such as those used byan accounting department, marketing department, engineering department,and so forth. Given the rapidly expanding volume of data undermanagement, companies also continue to seek innovative techniques formanaging data growth, for example by migrating data to lower-coststorage over time, reducing redundant data, pruning lower priority data,etc. Enterprises also increasingly view their stored data as a valuableasset and look for solutions that leverage their data. For instance,data analysis capabilities, information management, improved datapresentation and access features, and the like, are in increasingdemand.

SUMMARY

Typically, primary data in a native format residing on a clientcomputing device can be backed up, archived, or otherwise converted intosecondary copies in a secondary format by an information managementsystem and stored in a secondary storage device for later retrieval.When a user requests that the secondary copies be restored, theinformation management system may identify the location at which thesecondary copies are stored in the secondary storage device, retrievethe secondary copies from the identified location, convert the secondarycopies in the secondary format into primary data in the native format,and transmit the primary data to the client computing device.

In some cases, the process of retrieving the secondary copies form theidentified location and converting the secondary copies in the secondaryformat into primary data in the native format can introduce delaynoticeable to a user. For example, retrieval of the secondary copies canintroduce delay noticeable to a user if the drive on which the secondarycopies are stored has slow read and/or write times. In addition, thedelay may increase the higher the amount of primary data that the useris requesting to restore.

As a result, the user may have a better experience and the informationmanagement system may operate more efficiently if the restore delay canbe reduced. For example, a user may request primary data that the userhad recently requested be converted into secondary copies in a secondaryformat. In a typical information management system, the requestedprimary data may already have been converted into the secondary copiesin the secondary format and stored in the secondary storage device bythe time the request is received. Thus, the user may experience anoticeable restore delay. However, the restore delay could be reducedif, for example, the primary data in the native format is stored in astaging area or cache for a certain period of time before beingconverted into the secondary copies in the secondary format. Thus, therestore delay may be less noticeable or unnoticeable to a user incertain situations, such as when the user requests primary data thathappens to still reside in the staging area or cache.

Accordingly, described herein is an improved information managementsystem that implements a staging area or cache to temporarily storeprimary data in a native format before the primary data is convertedinto secondary copies in a secondary format and stored in a secondarystorage device. For example, the improved information management systemcan include various media agents that each include one or more highspeed drives (e.g., flash drives, solid state drives, etc.) and one ormore low speed drives (e.g., electromechanical disks, tape drives,etc.). When a client computing device provides primary data forconversion into secondary copies, the primary data can initially bestored in the native format in one or more of the high speed drives. Ifthe client computing device then submits a request for the primary data,the media agent can simply retrieve the primary data from the high speeddrive(s) and transmit the primary data to the client computing device.Because the primary data is already in the native format, no conversionoperations are performed by the media agent, thereby reducing therestore delay.

After a certain period of time, a media agent can take a file levelsnapshot of the primary data stored on the high speed drive(s). Before,during, and/or after taking the file level snapshot, the media agent candetermine which files that comprise the primary data have changed (ifany), store the changed files in the native format on one or more of thelow speed drives, and replace the primary data originally stored on thehigh speed drive(s) with stubs that reference the files stored on thelow speed drive(s). Thus, the primary data in the native format may nowbe stored on the low speed drive(s). If the client computing device thensubmits a request for the primary data, the media agent can simplyretrieve the primary data from the low speed drive(s) and transmit theprimary data to the client computing device. Because the primary data isalready in the native format, no conversion operations are performed bythe media agent, thereby reducing the restore delay. Because the readand/or write operations of the low speed drives may be slower than theread and/or write operations of the high speed drives, however, therestore delay may be higher than the restore delay experienced whenrestoring the primary data from the high speed drive(s). However, therestore delay may still be less than the restore delay produced bytypical information management systems.

After another period of time, a media agent can convert the primary datain the native format stored on the low speed drive(s) into secondarycopies in a secondary format and store the secondary copies in asecondary storage device. Thus, instead of immediately being convertedinto a secondary format and stored, the primary data can move betweendifferent storage tiers or levels, with the speed at which such primarydata can be restored increasing over time. Accordingly, the improvedinformation management system may provide rapid restore capabilitiesthat reduce the restore delay experienced by a user.

One aspect of the disclosure provides a networked information managementsystem. The networked information management system comprises a clientcomputing device having one or more first hardware processors, whereinthe client computing device executes an application that generated afirst file. The networked information management system furthercomprises one or more computing devices in communication with the clientcomputing device, wherein the one or more computing devices comprise afirst drive and a second drive, wherein the one or more computingdevices each have one or more second hardware processors, wherein theone or more computing devices are configured with computer-executableinstructions that, when executed, cause the one or more computingdevices to: process a request received from the client computing deviceto restore a version of a first file that existed at a first time;identify a snapshot stored in the first drive that is associated withthe first time and that includes a stub corresponding to the first file,wherein the stub references a storage location of the first file in thesecond drive; retrieve the first file from the storage location in thesecond drive based on the identified stub, wherein the first file isstored in the storage location in the second drive in a native format;transmit the first file retrieved from the storage location to theclient computing device; process a request received from the clientcomputing device to restore a version of the first file that existed ata second time before the first time; identify a second snapshot storedin the first drive that is associated with the second time and thatincludes a second stub corresponding to the first file, wherein thesecond stub references a second storage location of the first file inthe second drive; retrieve the first file from the second storagelocation in the second drive based on the identified second stub,wherein the first file is stored in the second storage location in thesecond drive in a secondary copy format; convert the first fileretrieved from the second storage location from the secondary copyformat to the native format; and transmit the converted first file tothe client computing device.

The networked information management system of the preceding paragraphcan include any sub-combination of the following features: where thecomputer-executable instructions, when executed, further cause the oneor more computing devices to shard the version of the first file thatexisted at the first time into a first file extent and a second fileextent; where the computer-executable instructions, when executed,further cause the one or more computing devices to: determine that therequest received from the client computing device corresponds to thesecond file extent, identify the snapshot stored in the first drive thatincludes the stub corresponding to the second file extent, retrieve thesecond file extent from the second drive based on the identified stub,and transmit the retrieved second file extent to the client computingdevice; where the computer-executable instructions, when executed,further cause the one or more computing devices to: receive an updatedversion of the first file, store the updated version of the first filein the first drive, determine that the first file has changed since aprevious snapshot operation, store the updated version of the first filein the second drive, create a second stub corresponding to the updatedversion of the first file, and create a skeleton directory in the firstdrive, wherein the skeleton directory comprises the second stub; wherethe computer-executable instructions, when executed, further cause theone or more computing devices to delete the updated version of the firstfile from the first drive; where the computer-executable instructions,when executed, further cause the one or more computing devices totransmit the first file retrieved from the storage location to theclient computing device without performing a conversion operation toconvert the first file into the native format; where the snapshot isstored in the first drive in association with the client computingdevice and the application executed by the client computing device;where the stub comprises an indication of the first file, a product IDidentifying a name of a computing system that stores the version of thefirst file that existed at the first time, a store ID identifying thatthe second drive stores the version of the first file that existed atthe first time, a universally unique identifier (UUID) identifying thestorage location of the version of the first file that existed at thefirst time in the second drive, and an indication of a time that thesnapshot was taken; where the first drive forms at least a portion of afirst type of file system, and wherein the second drive forms at least aportion of a second type of file system; and where read times of thesecond drive are slower than read times of the first drive.

Another aspect of the disclosure provides a computer-implemented methodcomprising: receiving, by one or more computing devices comprising afirst drive and a second drive, a request from a client computing deviceto restore a version of a first file that existed at a first time,wherein the first file is previously provided by the client computingdevice to the one or more computing devices, and wherein the first fileis generated by an application executed by the client computing device;identifying a snapshot stored in the first drive that is associated withthe first time and that includes a stub corresponding to the first file,wherein the stub references a storage location of the first file in thesecond drive; retrieving the first file from the storage location in thesecond drive based on the identified stub, wherein the first file isstored in the storage location in the second drive in a native format;transmitting the first file retrieved from the storage location to theclient computing device; processing a request received from the clientcomputing device to restore a version of the first file that existed ata second time before the first time; identifying a second snapshotstored in the first drive that is associated with the second time andthat includes a second stub corresponding to the first file, wherein thesecond stub references a second storage location of the first file inthe second drive; retrieving the first file from the second storagelocation in the second drive based on the identified second stub,wherein the first file is stored in the second storage location in thesecond drive in a secondary copy format; converting the first fileretrieved from the second storage location from the secondary copyformat to the native format; and transmitting the converted first fileto the client computing device.

The computer-implemented method of the preceding paragraph can includeany sub-combination of the following features: where thecomputer-implemented method further comprises sharding the version ofthe first file that existed at the first time into a first file extentand a second file extent; where the computer-implemented method furthercomprises: determining that the request received from the clientcomputing device corresponds to the second file extent, identifying thesnapshot stored in the first drive that includes the stub correspondingto the second file extent, retrieving the second file extent from thesecond drive based on the identified stub, and transmitting theretrieved second file extent to the client computing device; where thecomputer-implemented method further comprises: receiving an updatedversion of the first file, storing the updated version of the first filein the first drive, determining that the first file has changed since aprevious snapshot operation, storing the updated version of the firstfile in the second drive, creating a second stub corresponding to theupdated version of the first file, and creating a skeleton directory inthe first drive, wherein the skeleton directory comprises the secondstub; where transmitting the retrieved first file to the clientcomputing device further comprises transmitting the first file retrievedfrom the storage location to the client computing device withoutperforming a conversion operation to convert the first file into thenative format; where the snapshot is stored in the first drive inassociation with the client computing device and the applicationexecuted by the client computing device; where the stub comprises anindication of the first file, a product ID identifying a name of acomputing system that stores the version of the first file that existedat the first time, a store ID identifying that the second drive storesthe version of the first file that existed at the first time, auniversally unique identifier (UUID) identifying the storage location ofthe version of the first file that existed at the first time in thesecond drive, and an indication of a time that the snapshot was taken;where the first drive forms at least a portion of a first type of filesystem, and wherein the second drive forms at least a portion of asecond type of file system; and where read times of the second drive areslower than read times of the first drive.

Another aspect of the disclosure provides a non-transitorycomputer-readable medium storing instructions, which when executed byone or more computing devices comprising a first drive and a seconddrive, cause the one or more computing devices to perform a methodcomprising: receiving a request from a client computing device torestore a version of a first file that existed at a first time, whereinthe first file is previously provided by the client computing device tothe one or more computing devices, and wherein the first file isgenerated by an application executed by the client computing device;identifying a snapshot stored in the first drive that is associated withthe first time and that includes a stub corresponding to the first file,wherein the stub references a storage location of the first file in thesecond drive; retrieving the first file from the storage location in thesecond drive based on the identified stub, wherein the first file isstored in the storage location in the second drive in a native format;transmitting the first file retrieved from the storage location to theclient computing device; processing a request received from the clientcomputing device to restore a version of the first file that existed ata second time before the first time; identifying a second snapshotstored in the first drive that is associated with the second time andthat includes a second stub corresponding to the first file, wherein thesecond stub references a second storage location of the first file inthe second drive; retrieving the first file from the second storagelocation in the second drive based on the identified second stub,wherein the first file is stored in the second storage location in thesecond drive in a secondary copy format; converting the first fileretrieved from the second storage location from the secondary copyformat to the native format; and transmitting the converted first fileto the client computing device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a block diagram illustrating an exemplary informationmanagement system.

FIG. 1B is a detailed view of a primary storage device, a secondarystorage device, and some examples of primary data and secondary copydata.

FIG. 1C is a block diagram of an exemplary information management systemincluding a storage manager, one or more data agents, and one or moremedia agents.

FIG. 1D is a block diagram illustrating a scalable informationmanagement system.

FIG. 1E illustrates certain secondary copy operations according to anexemplary storage policy.

FIGS. 1F-1H are block diagrams illustrating suitable data structuresthat may be employed by the information management system.

FIG. 2A illustrates a system and technique for synchronizing primarydata to a destination such as a failover site using secondary copy data.

FIG. 2B illustrates an information management system architectureincorporating use of a network file system (NFS) protocol forcommunicating between the primary and secondary storage subsystems.

FIG. 2C is a block diagram of an example of a highly scalable manageddata pool architecture.

FIG. 3 is a block diagram illustrating some portions of a system forrapidly restoring primary data, according to an embodiment.

FIG. 4 illustrates a block diagram showing the operations performed tomove primary data between the different tiers.

FIG. 5 illustrates a block diagram showing the operations performed toenable rapid restore of primary data and/or secondary copies.

FIG. 6 is a block diagram illustrating additional components of the highspeed drives residing on the media agents.

FIG. 7 illustrates a block diagram showing the operations performed toread a file requested by a client computing device.

FIG. 8 illustrates a block diagram depicting various stubs and primarydata in a native format stored in the high speed drive(s) and the lowspeed drive(s).

FIG. 9 illustrates the structure of various snapshots.

FIG. 10 illustrates the structure of various snapshots after a fileextent is deleted.

FIG. 11 depicts some operations of a method for enabling rapid restoreof primary data and/or secondary copies, according to an embodiment.

FIG. 12 depicts some operations of a method for rapidly restoringprimary data and/or secondary copies, according to an embodiment.

DETAILED DESCRIPTION

Typically, primary data in a native format residing on a clientcomputing device can be backed up, archived, or otherwise converted intosecondary copies in a secondary format by an information managementsystem and stored in a secondary storage device for later retrieval.When a user requests that the secondary copies be restored, theinformation management system may identify the location at which thesecondary copies are stored in the secondary storage device, retrievethe secondary copies from the identified location, convert the secondarycopies in the secondary format into primary data in the native format,and transmit the primary data to the client computing device.

In some cases, the process of retrieving the secondary copies form theidentified location and converting the secondary copies in the secondaryformat into primary data in the native format can introduce delaynoticeable to a user. For example, retrieval of the secondary copies canintroduce delay noticeable to a user if the drive on which the secondarycopies are stored has slow read and/or write times. In addition, thedelay may increase the higher the amount of primary data that the useris requesting to restore.

As a result, the user may have a better experience and the informationmanagement system may operate more efficiently if the restore delay canbe reduced. For example, a user may request primary data that the userhad recently requested be converted into secondary copies in a secondaryformat. In a typical information management system, the requestedprimary data may already have been converted into the secondary copiesin the secondary format and stored in the secondary storage device bythe time the request is received. Thus, the user may experience anoticeable restore delay. However, the restore delay could be reducedif, for example, the primary data in the native format is stored in astaging area or cache for a certain period of time before beingconverted into the secondary copies in the secondary format. Thus, therestore delay may be less noticeable or unnoticeable to a user incertain situations, such as when the user requests primary data thathappens to still reside in the staging area or cache.

Accordingly, described herein is an improved information managementsystem that implements a staging area or cache to temporarily storeprimary data in a native format before the primary data is convertedinto secondary copies in a secondary format and stored in a secondarystorage device. For example, the improved information management systemcan include various media agents that each include one or more highspeed drives (e.g., flash drives, solid state drives, etc.) and one ormore low speed drives (e.g., electromechanical disks, tape drives,etc.). When a client computing device provides primary data forconversion into secondary copies, the primary data can initially bestored in the native format in one or more of the high speed drives. Ifthe client computing device then submits a request for the primary data,the media agent can simply retrieve the primary data from the high speeddrive(s) and transmit the primary data to the client computing device.Because the primary data is already in the native format, no conversionoperations are performed by the media agent, thereby reducing therestore delay.

After a certain period of time, a media agent can take a file levelsnapshot of the primary data stored on the high speed drive(s). Before,during, and/or after taking the file level snapshot, the media agent candetermine which files that comprise the primary data have changed (ifany), store the changed files in the native format on one or more of thelow speed drives, and replace the primary data originally stored on thehigh speed drive(s) with stubs that reference the files stored on thelow speed drive(s). Thus, the primary data in the native format may nowbe stored on the low speed drive(s). If the client computing device thensubmits a request for the primary data, the media agent can simplyretrieve the primary data from the low speed drive(s) and transmit theprimary data to the client computing device. Because the primary data isalready in the native format, no conversion operations are performed bythe media agent, thereby reducing the restore delay. Because the readand/or write operations of the low speed drives may be slower than theread and/or write operations of the high speed drives, however, therestore delay may be higher than the restore delay experienced whenrestoring the primary data from the high speed drive(s). However, therestore delay may still be less than the restore delay produced bytypical information management systems.

After another period of time, a media agent can convert the primary datain the native format stored on the low speed drive(s) into secondarycopies in a secondary format and store the secondary copies in asecondary storage device. Thus, instead of immediately being convertedinto a secondary format and stored, the primary data can move betweendifferent storage tiers or levels, with the speed at which such primarydata can be restored increasing over time. Accordingly, the improvedinformation management system may provide rapid restore capabilitiesthat reduce the restore delay experienced by a user.

Detailed descriptions and examples of systems and methods according toone or more embodiments may be found in the section entitled RapidRestore, as well as in the section entitled Example Embodiments, andalso in FIGS. 3 through 12 herein. Furthermore, components andfunctionality for the rapid restore capabilities may be configuredand/or incorporated into information management systems such as thosedescribed herein in FIGS. 1A-1H and 2A-2C.

Various embodiments described herein are intimately tied to, enabled by,and would not exist except for, computer technology. For example, therapid restore capabilities described herein in reference to variousembodiments cannot reasonably be performed by humans alone, without thecomputer technology upon which they are implemented.

Information Management System Overview

With the increasing importance of protecting and leveraging data,organizations simply cannot risk losing critical data. Moreover, runawaydata growth and other modern realities make protecting and managing dataincreasingly difficult. There is therefore a need for efficient,powerful, and user-friendly solutions for protecting and managing dataand for smart and efficient management of data storage. Depending on thesize of the organization, there may be many data production sourceswhich are under the purview of tens, hundreds, or even thousands ofindividuals. In the past, individuals were sometimes responsible formanaging and protecting their own data, and a patchwork of hardware andsoftware point solutions may have been used in any given organization.These solutions were often provided by different vendors and had limitedor no interoperability. Certain embodiments described herein addressthese and other shortcomings of prior approaches by implementingscalable, unified, organization-wide information management, includingdata storage management.

FIG. 1A shows one such information management system 100 (or “system100”), which generally includes combinations of hardware and softwareconfigured to protect and manage data and metadata that are generatedand used by computing devices in system 100. System 100 may be referredto in some embodiments as a “storage management system” or a “datastorage management system.” System 100 performs information managementoperations, some of which may be referred to as “storage operations” or“data storage operations,” to protect and manage the data residing inand/or managed by system 100. The organization that employs system 100may be a corporation or other business entity, non-profit organization,educational institution, household, governmental agency, or the like.

Generally, the systems and associated components described herein may becompatible with and/or provide some or all of the functionality of thesystems and corresponding components described in one or more of thefollowing U.S. patents/publications and patent applications assigned toCommvault Systems, Inc., each of which is hereby incorporated byreference in its entirety herein:

-   U.S. Pat. No. 7,035,880, entitled “Modular Backup and Retrieval    System Used in Conjunction With a Storage Area Network”;-   U.S. Pat. No. 7,107,298, entitled “System And Method For Archiving    Objects In An Information Store”;-   U.S. Pat. No. 7,246,207, entitled “System and Method for Dynamically    Performing Storage Operations in a Computer Network”;-   U.S. Pat. No. 7,315,923, entitled “System And Method For Combining    Data Streams In Pipelined Storage Operations In A Storage Network”;-   U.S. Pat. No. 7,343,453, entitled “Hierarchical Systems and Methods    for Providing a Unified View of Storage Information”;-   U.S. Pat. No. 7,395,282, entitled “Hierarchical Backup and Retrieval    System”;-   U.S. Pat. No. 7,529,782, entitled “System and Methods for Performing    a Snapshot and for Restoring Data”;-   U.S. Pat. No. 7,617,262, entitled “System and Methods for Monitoring    Application Data in a Data Replication System”;-   U.S. Pat. No. 7,734,669, entitled “Managing Copies Of Data”; U.S.    Pat. No. 7,747,579, entitled “Metabase for Facilitating Data    Classification”;-   U.S. Pat. No. 8,156,086, entitled “Systems And Methods For Stored    Data Verification”;-   U.S. Pat. No. 8,170,995, entitled “Method and System for Offline    Indexing of Content and Classifying Stored Data”;-   U.S. Pat. No. 8,230,195, entitled “System And Method For Performing    Auxiliary Storage Operations”;-   U.S. Pat. No. 8,285,681, entitled “Data Object Store and Server for    a Cloud Storage Environment, Including Data Deduplication and Data    Management Across Multiple Cloud Storage Sites”;-   U.S. Pat. No. 8,307,177, entitled “Systems And Methods For    Management Of Virtualization Data”;-   U.S. Pat. No. 8,364,652, entitled “Content-Aligned, Block-Based    Deduplication”;-   U.S. Pat. No. 8,578,120, entitled “Block-Level Single Instancing”;-   U.S. Pat. No. 8,954,446, entitled “Client-Side Repository in a    Networked Deduplicated Storage System”;-   U.S. Pat. No. 9,020,900, entitled “Distributed Deduplicated Storage    System”;-   U.S. Pat. No. 9,098,495, entitled “Application-Aware and Remote    Single Instance Data Management”;-   U.S. Pat. No. 9,239,687, entitled “Systems and Methods for Retaining    and Using Data Block Signatures in Data Protection Operations”;-   U.S. Patent Application Pub. No. 2006/0224846, entitled “System and    Method to Support Single Instance Storage Operations”;-   U.S. Patent Application Pub. No. 2014/0201170, entitled “High    Availability Distributed Deduplicated Storage System”;-   U.S. Patent Application Pub. No. 2016/0350391, entitled “Replication    Using Deduplicated Secondary Copy Data”;-   U.S. Patent Application Pub. No. 2017/0168903 entitled “Live    Synchronization and Management of Virtual Machines across Computing    and Virtualization Platforms and Using Live Synchronization to    Support Disaster Recovery”;-   U.S. Patent Application Pub. No. 2017/0193003 entitled “Redundant    and Robust Distributed Deduplication Data Storage System”;-   U.S. Patent Application Pub. No. 2017/0235647 entitled “Data    Protection Operations Based on Network Path Information”;-   U.S. Patent Application Pub. No. 2017/0242871, entitled “Data    Restoration Operations Based on Network Path Information”; and-   U.S. Patent Application Pub. No. 2017/0185488, entitled    “Application-Level Live Synchronization Across Computing Platforms    Including Synchronizing Co-Resident Applications To Disparate    Standby Destinations And Selectively Synchronizing Some Applications    And Not Others”.

System 100 includes computing devices and computing technologies. Forinstance, system 100 can include one or more client computing devices102 and secondary storage computing devices 106, as well as storagemanager 140 or a host computing device for it. Computing devices caninclude, without limitation, one or more: workstations, personalcomputers, desktop computers, or other types of generally fixedcomputing systems such as mainframe computers, servers, andminicomputers. Other computing devices can include mobile or portablecomputing devices, such as one or more laptops, tablet computers,personal data assistants, mobile phones (such as smartphones), and othermobile or portable computing devices such as embedded computers, set topboxes, vehicle-mounted devices, wearable computers, etc. Servers caninclude mail servers, file servers, database servers, virtual machineservers, and web servers. Any given computing device comprises one ormore processors (e.g., CPU and/or single-core or multi-core processors),as well as corresponding non-transitory computer memory (e.g.,random-access memory (RAM)) for storing computer programs which are tobe executed by the one or more processors. Other computer memory formass storage of data may be packaged/configured with the computingdevice (e.g., an internal hard disk) and/or may be external andaccessible by the computing device (e.g., network-attached storage, astorage array, etc.). In some cases, a computing device includes cloudcomputing resources, which may be implemented as virtual machines. Forinstance, one or more virtual machines may be provided to theorganization by a third-party cloud service vendor.

In some embodiments, computing devices can include one or more virtualmachine(s) running on a physical host computing device (or “hostmachine”) operated by the organization. As one example, the organizationmay use one virtual machine as a database server and another virtualmachine as a mail server, both virtual machines operating on the samehost machine. A Virtual machine (“VM”) is a software implementation of acomputer that does not physically exist and is instead instantiated inan operating system of a physical computer (or host machine) to enableapplications to execute within the VM’s environment, i.e., a VM emulatesa physical computer. A VM includes an operating system and associatedvirtual resources, such as computer memory and processor(s). Ahypervisor operates between the VM and the hardware of the physical hostmachine and is generally responsible for creating and running the VMs.Hypervisors are also known in the art as virtual machine monitors or avirtual machine managers or “VMMs”, and may be implemented in software,firmware, and/or specialized hardware installed on the host machine.Examples of hypervisors include ESX Server, by VMware, Inc. of PaloAlto, California; Microsoft Virtual Server and Microsoft Windows ServerHyper-V, both by Microsoft Corporation of Redmond, Washington; Sun xVMby Oracle America Inc. of Santa Clara, California; and Xen by CitrixSystems, Santa Clara, California. The hypervisor provides resources toeach virtual operating system such as a virtual processor, virtualmemory, a virtual network device, and a virtual disk. Each virtualmachine has one or more associated virtual disks. The hypervisortypically stores the data of virtual disks in files on the file systemof the physical host machine, called virtual machine disk files (“VMDK”in VMware lingo) or virtual hard disk image files (in Microsoft lingo).For example, VMware’s ESX Server provides the Virtual Machine FileSystem (VMFS) for the storage of virtual machine disk files. A virtualmachine reads data from and writes data to its virtual disk much the waythat a physical machine reads data from and writes data to a physicaldisk. Examples of techniques for implementing information management ina cloud computing environment are described in U.S. Pat. No. 8,285,681.Examples of techniques for implementing information management in avirtualized computing environment are described in U.S. Pat. No.8,307,177.

Information management system 100 can also include electronic datastorage devices, generally used for mass storage of data, including,e.g., primary storage devices 104 and secondary storage devices 108.Storage devices can generally be of any suitable type including, withoutlimitation, disk drives, storage arrays (e.g., storage-area network(SAN) and/or network-attached storage (NAS) technology), semiconductormemory (e.g., solid state storage devices), network attached storage(NAS) devices, tape libraries, or other magnetic, non-tape storagedevices, optical media storage devices, DNA/RNA-based memory technology,combinations of the same, etc. In some embodiments, storage devices formpart of a distributed file system. In some cases, storage devices areprovided in a cloud storage environment (e.g., a private cloud or oneoperated by a third-party vendor), whether for primary data or secondarycopies or both.

Depending on context, the term “information management system” can referto generally all of the illustrated hardware and software components inFIG. 1C, or the term may refer to only a subset of the illustratedcomponents. For instance, in some cases, system 100 generally refers toa combination of specialized components used to protect, move, manage,manipulate, analyze, and/or process data and metadata generated byclient computing devices 102. However, system 100 in some cases does notinclude the underlying components that generate and/or store primarydata 112, such as the client computing devices 102 themselves, and theprimary storage devices 104. Likewise secondary storage devices 108(e.g., a third-party provided cloud storage environment) may not be partof system 100. As an example, “information management system” or“storage management system” may sometimes refer to one or more of thefollowing components, which will be described in further detail below:storage manager, data agent, and media agent.

One or more client computing devices 102 may be part of system 100, eachclient computing device 102 having an operating system and at least oneapplication 110 and one or more accompanying data agents executingthereon; and associated with one or more primary storage devices 104storing primary data 112. Client computing device(s) 102 and primarystorage devices 104 may generally be referred to in some cases asprimary storage subsystem 117.

Client Computing Devices, Clients, and Subclients

Typically, a variety of sources in an organization produce data to beprotected and managed. As just one example, in a corporate environmentsuch data sources can be employee workstations and company servers suchas a mail server, a web server, a database server, a transaction server,or the like. In system 100, data generation sources include one or moreclient computing devices 102. A computing device that has a data agent142 installed and operating on it is generally referred to as a “clientcomputing device” 102, and may include any type of computing device,without limitation. A client computing device 102 may be associated withone or more users and/or user accounts.

A “client” is a logical component of information management system 100,which may represent a logical grouping of one or more data agentsinstalled on a client computing device 102. Storage manager 140recognizes a client as a component of system 100, and in someembodiments, may automatically create a client component the first timea data agent 142 is installed on a client computing device 102. Becausedata generated by executable component(s) 110 is tracked by theassociated data agent 142 so that it may be properly protected in system100, a client may be said to generate data and to store the generateddata to primary storage, such as primary storage device 104. However,the terms “client” and “client computing device” as used herein do notimply that a client computing device 102 is necessarily configured inthe client/server sense relative to another computing device such as amail server, or that a client computing device 102 cannot be a server inits own right. As just a few examples, a client computing device 102 canbe and/or include mail servers, file servers, database servers, virtualmachine servers, and/or web servers.

Each client computing device 102 may have application(s) 110 executingthereon which generate and manipulate the data that is to be protectedfrom loss and managed in system 100. Applications 110 generallyfacilitate the operations of an organization, and can include, withoutlimitation, mail server applications (e.g., Microsoft Exchange Server),file system applications, mail client applications (e.g., MicrosoftExchange Client), database applications or database management systems(e.g., SQL, Oracle, SAP, Lotus Notes Database), word processingapplications (e.g., Microsoft Word), spreadsheet applications, financialapplications, presentation applications, graphics and/or videoapplications, browser applications, mobile applications, entertainmentapplications, and so on. Each application 110 may be accompanied by anapplication-specific data agent 142, though not all data agents 142 areapplication-specific or associated with only application. A file system,e.g., Microsoft Windows Explorer, may be considered an application 110and may be accompanied by its own data agent 142. Client computingdevices 102 can have at least one operating system (e.g., MicrosoftWindows, Mac OS X, iOS, IBM z/OS, Linux, other Unix-based operatingsystems, etc.) installed thereon, which may support or host one or morefile systems and other applications 110. In some embodiments, a virtualmachine that executes on a host client computing device 102 may beconsidered an application 110 and may be accompanied by a specific dataagent 142 (e.g., virtual server data agent).

Client computing devices 102 and other components in system 100 can beconnected to one another via one or more electronic communicationpathways 114. For example, a first communication pathway 114 maycommunicatively couple client computing device 102 and secondary storagecomputing device 106; a second communication pathway 114 maycommunicatively couple storage manager 140 and client computing device102; and a third communication pathway 114 may communicatively couplestorage manager 140 and secondary storage computing device 106, etc.(see, e.g., FIG. 1A and FIG. 1C). A communication pathway 114 caninclude one or more networks or other connection types including one ormore of the following, without limitation: the Internet, a wide areanetwork (WAN), a local area network (LAN), a Storage Area Network (SAN),a Fibre Channel (FC) connection, a Small Computer System Interface(SCSI) connection, a virtual private network (VPN), a token ring orTCP/IP based network, an intranet network, a point-to-point link, acellular network, a wireless data transmission system, a two-way cablesystem, an interactive kiosk network, a satellite network, a broadbandnetwork, a baseband network, a neural network, a mesh network, an ad hocnetwork, other appropriate computer or telecommunications networks,combinations of the same or the like. Communication pathways 114 in somecases may also include application programming interfaces (APIs)including, e.g., cloud service provider APIs, virtual machine managementAPIs, and hosted service provider APIs. The underlying infrastructure ofcommunication pathways 114 may be wired and/or wireless, analog and/ordigital, or any combination thereof; and the facilities used may beprivate, public, third-party provided, or any combination thereof,without limitation.

A “subclient” is a logical grouping of all or part of a client’s primarydata 112. In general, a subclient may be defined according to how thesubclient data is to be protected as a unit in system 100. For example,a subclient may be associated with a certain storage policy. A givenclient may thus comprise several subclients, each subclient associatedwith a different storage policy. For example, some files may form afirst subclient that requires compression and deduplication and isassociated with a first storage policy. Other files of the client mayform a second subclient that requires a different retention schedule aswell as encryption, and may be associated with a different, secondstorage policy. As a result, though the primary data may be generated bythe same application 110 and may belong to one given client, portions ofthe data may be assigned to different subclients for distinct treatmentby system 100. More detail on subclients is given in regard to storagepolicies below.

Primary Data and Exemplary Primary Storage Devices

Primary data 112 is generally production data or “live” data generatedby the operating system and/or applications 110 executing on clientcomputing device 102. Primary data 112 is generally stored on primarystorage device(s) 104 and is organized via a file system operating onthe client computing device 102. Thus, client computing device(s) 102and corresponding applications 110 may create, access, modify, write,delete, and otherwise use primary data 112. Primary data 112 isgenerally in the native format of the source application 110. Primarydata 112 is an initial or first stored body of data generated by thesource application 110. Primary data 112 in some cases is createdsubstantially directly from data generated by the corresponding sourceapplication 110. It can be useful in performing certain tasks toorganize primary data 112 into units of different granularities. Ingeneral, primary data 112 can include files, directories, file systemvolumes, data blocks, extents, or any other hierarchies or organizationsof data objects. As used herein, a “data object” can refer to (i) anyfile that is currently addressable by a file system or that waspreviously addressable by the file system (e.g., an archive file),and/or to (ii) a subset of such a file (e.g., a data block, an extent,etc.). Primary data 112 may include structured data (e.g., databasefiles), unstructured data (e.g., documents), and/or semi-structureddata. See, e.g., FIG. 1B.

It can also be useful in performing certain functions of system 100 toaccess and modify metadata within primary data 112. Metadata generallyincludes information about data objects and/or characteristicsassociated with the data objects. For simplicity herein, it is to beunderstood that, unless expressly stated otherwise, any reference toprimary data 112 generally also includes its associated metadata, butreferences to metadata generally do not include the primary data.Metadata can include, without limitation, one or more of the following:the data owner (e.g., the client or user that generates the data), thelast modified time (e.g., the time of the most recent modification ofthe data object), a data object name (e.g., a file name), a data objectsize (e.g., a number of bytes of data), information about the content(e.g., an indication as to the existence of a particular search term),user-supplied tags, to/from information for email (e.g., an emailsender, recipient, etc.), creation date, file type (e.g., format orapplication type), last accessed time, application type (e.g., type ofapplication that generated the data object), location/network (e.g., acurrent, past or future location of the data object and network pathwaysto/from the data object), geographic location (e.g., GPS coordinates),frequency of change (e.g., a period in which the data object ismodified), business unit (e.g., a group or department that generates,manages or is otherwise associated with the data object), aginginformation (e.g., a schedule, such as a time period, in which the dataobject is migrated to secondary or long term storage), boot sectors,partition layouts, file location within a file folder directorystructure, user permissions, owners, groups, access control lists(ACLs), system metadata (e.g., registry information), combinations ofthe same or other similar information related to the data object. Inaddition to metadata generated by or related to file systems andoperating systems, some applications 110 and/or other components ofsystem 100 maintain indices of metadata for data objects, e.g., metadataassociated with individual email messages. The use of metadata toperform classification and other functions is described in greaterdetail below.

Primary storage devices 104 storing primary data 112 may be relativelyfast and/or expensive technology (e.g., flash storage, a disk drive, ahard-disk storage array, solid state memory, etc.), typically to supporthigh-performance live production environments. Primary data 112 may behighly changeable and/or may be intended for relatively short termretention (e.g., hours, days, or weeks). According to some embodiments,client computing device 102 can access primary data 112 stored inprimary storage device 104 by making conventional file system calls viathe operating system. Each client computing device 102 is generallyassociated with and/or in communication with one or more primary storagedevices 104 storing corresponding primary data 112. A client computingdevice 102 is said to be associated with or in communication with aparticular primary storage device 104 if it is capable of one or moreof: routing and/or storing data (e.g., primary data 112) to the primarystorage device 104, coordinating the routing and/or storing of data tothe primary storage device 104, retrieving data from the primary storagedevice 104, coordinating the retrieval of data from the primary storagedevice 104, and modifying and/or deleting data in the primary storagedevice 104. Thus, a client computing device 102 may be said to accessdata stored in an associated storage device 104.

Primary storage device 104 may be dedicated or shared. In some cases,each primary storage device 104 is dedicated to an associated clientcomputing device 102, e.g., a local disk drive. In other cases, one ormore primary storage devices 104 can be shared by multiple clientcomputing devices 102, e.g., via a local network, in a cloud storageimplementation, etc. As one example, primary storage device 104 can be astorage array shared by a group of client computing devices 102, such asEMC Clariion, EMC Symmetrix, EMC Celerra, Dell EqualLogic, IBM XIV,NetApp FAS, HP EVA, and HP 3PAR.

System 100 may also include hosted services (not shown), which may behosted in some cases by an entity other than the organization thatemploys the other components of system 100. For instance, the hostedservices may be provided by online service providers. Such serviceproviders can provide social networking services, hosted email services,or hosted productivity applications or other hosted applications such assoftware-as-a-service (SaaS), platform-as-a-service (PaaS), applicationservice providers (ASPs), cloud services, or other mechanisms fordelivering functionality via a network. As it services users, eachhosted service may generate additional data and metadata, which may bemanaged by system 100, e.g., as primary data 112. In some cases, thehosted services may be accessed using one of the applications 110. As anexample, a hosted mail service may be accessed via browser running on aclient computing device 102.

Secondary Copies and Exemplary Secondary Storage Devices

Primary data 112 stored on primary storage devices 104 may becompromised in some cases, such as when an employee deliberately oraccidentally deletes or overwrites primary data 112. Or primary storagedevices 104 can be damaged, lost, or otherwise corrupted. For recoveryand/or regulatory compliance purposes, it is therefore useful togenerate and maintain copies of primary data 112. Accordingly, system100 includes one or more secondary storage computing devices 106 and oneor more secondary storage devices 108 configured to create and store oneor more secondary copies 116 of primary data 112 including itsassociated metadata. The secondary storage computing devices 106 and thesecondary storage devices 108 may be referred to as secondary storagesubsystem 118.

Secondary copies 116 can help in search and analysis efforts and meetother information management goals as well, such as: restoring dataand/or metadata if an original version is lost (e.g., by deletion,corruption, or disaster); allowing point-in-time recovery; complyingwith regulatory data retention and electronic discovery (e-discovery)requirements; reducing utilized storage capacity in the productionsystem and/or in secondary storage; facilitating organization and searchof data; improving user access to data files across multiple computingdevices and/or hosted services; and implementing data retention andpruning policies.

A secondary copy 116 can comprise a separate stored copy of data that isderived from one or more earlier-created stored copies (e.g., derivedfrom primary data 112 or from another secondary copy 116). Secondarycopies 116 can include point-in-time data, and may be intended forrelatively long-term retention before some or all of the data is movedto other storage or discarded. In some cases, a secondary copy 116 maybe in a different storage device than other previously stored copies;and/or may be remote from other previously stored copies. Secondarycopies 116 can be stored in the same storage device as primary data 112.For example, a disk array capable of performing hardware snapshotsstores primary data 112 and creates and stores hardware snapshots of theprimary data 112 as secondary copies 116. Secondary copies 116 may bestored in relatively slow and/or lower cost storage (e.g., magnetictape). A secondary copy 116 may be stored in a backup or archive format,or in some other format different from the native source applicationformat or other format of primary data 112.

Secondary storage computing devices 106 may index secondary copies 116(e.g., using a media agent 144), enabling users to browse and restore ata later time and further enabling the lifecycle management of theindexed data. After creation of a secondary copy 116 that representscertain primary data 112, a pointer or other location indicia (e.g., astub) may be placed in primary data 112, or be otherwise associated withprimary data 112, to indicate the current location of a particularsecondary copy 116. Since an instance of a data object or metadata inprimary data 112 may change over time as it is modified by application110 (or hosted service or the operating system), system 100 may createand manage multiple secondary copies 116 of a particular data object ormetadata, each copy representing the state of the data object in primarydata 112 at a particular point in time. Moreover, since an instance of adata object in primary data 112 may eventually be deleted from primarystorage device 104 and the file system, system 100 may continue tomanage point-in-time representations of that data object, even thoughthe instance in primary data 112 no longer exists. For virtual machines,the operating system and other applications 110 of client computingdevice(s) 102 may execute within or under the management ofvirtualization software (e.g., a VMM), and the primary storage device(s)104 may comprise a virtual disk created on a physical storage device.System 100 may create secondary copies 116 of the files or other dataobjects in a virtual disk file and/or secondary copies 116 of the entirevirtual disk file itself (e.g., of an entire .vmdk file).

Secondary copies 116 are distinguishable from corresponding primary data112. First, secondary copies 116 can be stored in a different formatfrom primary data 112 (e.g., backup, archive, or other non-nativeformat). For this or other reasons, secondary copies 116 may not bedirectly usable by applications 110 or client computing device 102(e.g., via standard system calls or otherwise) without modification,processing, or other intervention by system 100 which may be referred toas “restore” operations. Secondary copies 116 may have been processed bydata agent 142 and/or media agent 144 in the course of being created(e.g., compression, deduplication, encryption, integrity markers,indexing, formatting, application-aware metadata, etc.), and thussecondary copy 116 may represent source primary data 112 withoutnecessarily being exactly identical to the source.

Second, secondary copies 116 may be stored on a secondary storage device108 that is inaccessible to application 110 running on client computingdevice 102 and/or hosted service. Some secondary copies 116 may be“offline copies,” in that they are not readily available (e.g., notmounted to tape or disk). Offline copies can include copies of data thatsystem 100 can access without human intervention (e.g., tapes within anautomated tape library, but not yet mounted in a drive), and copies thatthe system 100 can access only with some human intervention (e.g., tapeslocated at an offsite storage site).

Using Intermediate Devices for Creating Secondary Copies - SecondaryStorage Computing Devices

Creating secondary copies can be challenging when hundreds or thousandsof client computing devices 102 continually generate large volumes ofprimary data 112 to be protected. Also, there can be significantoverhead involved in the creation of secondary copies 116. Moreover,specialized programmed intelligence and/or hardware capability isgenerally needed for accessing and interacting with secondary storagedevices 108. Client computing devices 102 may interact directly with asecondary storage device 108 to create secondary copies 116, but in viewof the factors described above, this approach can negatively impact theability of client computing device 102 to serve/service application 110and produce primary data 112. Further, any given client computing device102 may not be optimized for interaction with certain secondary storagedevices 108.

Thus, system 100 may include one or more software and/or hardwarecomponents which generally act as intermediaries between clientcomputing devices 102 (that generate primary data 112) and secondarystorage devices 108 (that store secondary copies 116). In addition tooff-loading certain responsibilities from client computing devices 102,these intermediate components provide other benefits. For instance, asdiscussed further below with respect to FIG. 1D, distributing some ofthe work involved in creating secondary copies 116 can enhancescalability and improve system performance. For instance, usingspecialized secondary storage computing devices 106 and media agents 144for interfacing with secondary storage devices 108 and/or for performingcertain data processing operations can greatly improve the speed withwhich system 100 performs information management operations and can alsoimprove the capacity of the system to handle large numbers of suchoperations, while reducing the computational load on the productionenvironment of client computing devices 102. The intermediate componentscan include one or more secondary storage computing devices 106 as shownin FIG. 1A and/or one or more media agents 144. Media agents arediscussed further below (e.g., with respect to FIGS. 1C-1E). Thesespecial-purpose components of system 100 comprise specialized programmedintelligence and/or hardware capability for writing to, reading from,instructing, communicating with, or otherwise interacting with secondarystorage devices 108.

Secondary storage computing device(s) 106 can comprise any of thecomputing devices described above, without limitation. In some cases,secondary storage computing device(s) 106 also include specializedhardware componentry and/or software intelligence (e.g., specializedinterfaces) for interacting with certain secondary storage device(s) 108with which they may be specially associated.

To create a secondary copy 116 involving the copying of data fromprimary storage subsystem 117 to secondary storage subsystem 118, clientcomputing device 102 may communicate the primary data 112 to be copied(or a processed version thereof generated by a data agent 142) to thedesignated secondary storage computing device 106, via a communicationpathway 114. Secondary storage computing device 106 in turn may furtherprocess and convey the data or a processed version thereof to secondarystorage device 108. One or more secondary copies 116 may be created fromexisting secondary copies 116, such as in the case of an auxiliary copyoperation, described further below.

Exemplary Primary Data and an Exemplary Secondary Copy

FIG. 1B is a detailed view of some specific examples of primary datastored on primary storage device(s) 104 and secondary copy data storedon secondary storage device(s) 108, with other components of the systemremoved for the purposes of illustration. Stored on primary storagedevice(s) 104 are primary data 112 objects including word processingdocuments 119A-B, spreadsheets 120, presentation documents 122, videofiles 124, image files 126, email mailboxes 128 (and corresponding emailmessages 129A-C), HTML/XML or other types of markup language files 130,databases 132 and corresponding tables or other data structures133A-133C. Some or all primary data 112 objects are associated withcorresponding metadata (e.g., “Meta1-11”), which may include file systemmetadata and/or application-specific metadata. Stored on the secondarystorage device(s) 108 are secondary copy 116 data objects 134A-C whichmay include copies of or may otherwise represent corresponding primarydata 112.

Secondary copy data objects 134A-C can individually represent more thanone primary data object. For example, secondary copy data object 134Arepresents three separate primary data objects 133C, 122, and 129C(represented as 133C′, 122′, and 129C′, respectively, and accompanied bycorresponding metadata Meta11, Meta3, and Meta8, respectively).Moreover, as indicated by the prime mark (′), secondary storagecomputing devices 106 or other components in secondary storage subsystem118 may process the data received from primary storage subsystem 117 andstore a secondary copy including a transformed and/or supplementedrepresentation of a primary data object and/or metadata that isdifferent from the original format, e.g., in a compressed, encrypted,deduplicated, or other modified format. For instance, secondary storagecomputing devices 106 can generate new metadata or other informationbased on said processing, and store the newly generated informationalong with the secondary copies. Secondary copy data object 134Brepresents primary data objects 120, 133B, and 119A as 120′, 133B′, and119A′, respectively, accompanied by corresponding metadata Meta2,Meta10, and Meta1, respectively. Also, secondary copy data object 134Crepresents primary data objects 133A, 119B, and 129A as 133A′, 119B′,and 129A′, respectively, accompanied by corresponding metadata Meta9,Meta5, and Meta6, respectively.

Exemplary Information Management System Architecture

System 100 can incorporate a variety of different hardware and softwarecomponents, which can in turn be organized with respect to one anotherin many different configurations, depending on the embodiment. There arecritical design choices involved in specifying the functionalresponsibilities of the components and the role of each component insystem 100. Such design choices can impact how system 100 performs andadapts to data growth and other changing circumstances. FIG. 1C shows asystem 100 designed according to these considerations and includes:storage manager 140, one or more data agents 142 executing on clientcomputing device(s) 102 and configured to process primary data 112, andone or more media agents 144 executing on one or more secondary storagecomputing devices 106 for performing tasks involving secondary storagedevices 108.

Storage Manager

Storage manager 140 is a centralized storage and/or information managerthat is configured to perform certain control functions and also tostore certain critical information about system 100 - hence storagemanager 140 is said to manage system 100. As noted, the number ofcomponents in system 100 and the amount of data under management can belarge. Managing the components and data is therefore a significant task,which can grow unpredictably as the number of components and data scaleto meet the needs of the organization. For these and other reasons,according to certain embodiments, responsibility for controlling system100, or at least a significant portion of that responsibility, isallocated to storage manager 140. Storage manager 140 can be adaptedindependently according to changing circumstances, without having toreplace or re-design the remainder of the system. Moreover, a computingdevice for hosting and/or operating as storage manager 140 can beselected to best suit the functions and networking needs of storagemanager 140. These and other advantages are described in further detailbelow and with respect to FIG. 1D.

Storage manager 140 may be a software module or other application hostedby a suitable computing device. In some embodiments, storage manager 140is itself a computing device that performs the functions describedherein. Storage manager 140 comprises or operates in conjunction withone or more associated data structures such as a dedicated database(e.g., management database 146), depending on the configuration. Thestorage manager 140 generally initiates, performs, coordinates, and/orcontrols storage and other information management operations performedby system 100, e.g., to protect and control primary data 112 andsecondary copies 116. In general, storage manager 140 is said to managesystem 100, which includes communicating with, instructing, andcontrolling in some circumstances components such as data agents 142 andmedia agents 144, etc.

As shown by the dashed arrowed lines 114 in FIG. 1C, storage manager 140may communicate with, instruct, and/or control some or all elements ofsystem 100, such as data agents 142 and media agents 144. In thismanner, storage manager 140 manages the operation of various hardwareand software components in system 100. In certain embodiments, controlinformation originates from storage manager 140 and status as well asindex reporting is transmitted to storage manager 140 by the managedcomponents, whereas payload data and metadata are generally communicatedbetween data agents 142 and media agents 144 (or otherwise betweenclient computing device(s) 102 and secondary storage computing device(s)106), e.g., at the direction of and under the management of storagemanager 140. Control information can generally include parameters andinstructions for carrying out information management operations, suchas, without limitation, instructions to perform a task associated withan operation, timing information specifying when to initiate a task,data path information specifying what components to communicate with oraccess in carrying out an operation, and the like. In other embodiments,some information management operations are controlled or initiated byother components of system 100 (e.g., by media agents 144 or data agents142), instead of or in combination with storage manager 140.

According to certain embodiments, storage manager 140 provides one ormore of the following functions:

-   communicating with data agents 142 and media agents 144, including    transmitting instructions, messages, and/or queries, as well as    receiving status reports, index information, messages, and/or    queries, and responding to same;-   initiating execution of information management operations;-   initiating restore and recovery operations;-   managing secondary storage devices 108 and inventory/capacity of the    same;-   allocating secondary storage devices 108 for secondary copy    operations;-   reporting, searching, and/or classification of data in system 100;-   monitoring completion of and status reporting related to information    management operations and jobs;-   tracking movement of data within system 100;-   tracking age information relating to secondary copies 116, secondary    storage devices 108, comparing the age information against retention    guidelines, and initiating data pruning when appropriate;-   tracking logical associations between components in system 100;-   protecting metadata associated with system 100, e.g., in management    database 146;-   implementing job management, schedule management, event management,    alert management, reporting, job history maintenance, user security    management, disaster recovery management, and/or user interfacing    for system administrators and/or end users of system 100;-   sending, searching, and/or viewing of log files; and-   implementing operations management functionality.

Storage manager 140 may maintain an associated database 146 (or “storagemanager database 146” or “management database 146”) ofmanagement-related data and information management policies 148.Database 146 is stored in computer memory accessible by storage manager140. Database 146 may include a management index 150 (or “index 150”) orother data structure(s) that may store: logical associations betweencomponents of the system; user preferences and/or profiles (e.g.,preferences regarding encryption, compression, or deduplication ofprimary data or secondary copies; preferences regarding the scheduling,type, or other aspects of secondary copy or other operations; mappingsof particular information management users or user accounts to certaincomputing devices or other components, etc.; management tasks; mediacontainerization; other useful data; and/or any combination thereof. Forexample, storage manager 140 may use index 150 to track logicalassociations between media agents 144 and secondary storage devices 108and/or movement of data to/from secondary storage devices 108. Forinstance, index 150 may store data associating a client computing device102 with a particular media agent 144 and/or secondary storage device108, as specified in an information management policy 148.

Administrators and others may configure and initiate certain informationmanagement operations on an individual basis. But while this may beacceptable for some recovery operations or other infrequent tasks, it isoften not workable for implementing ongoing organization-wide dataprotection and management. Thus, system 100 may utilize informationmanagement policies 148 for specifying and executing informationmanagement operations on an automated basis. Generally, an informationmanagement policy 148 can include a stored data structure or otherinformation source that specifies parameters (e.g., criteria and rules)associated with storage management or other information managementoperations. Storage manager 140 can process an information managementpolicy 148 and/or index 150 and, based on the results, identify aninformation management operation to perform, identify the appropriatecomponents in system 100 to be involved in the operation (e.g., clientcomputing devices 102 and corresponding data agents 142, secondarystorage computing devices 106 and corresponding media agents 144, etc.),establish connections to those components and/or between thosecomponents, and/or instruct and control those components to carry outthe operation. In this manner, system 100 can translate storedinformation into coordinated activity among the various computingdevices in system 100.

Management database 146 may maintain information management policies 148and associated data, although information management policies 148 can bestored in computer memory at any appropriate location outside managementdatabase 146. For instance, an information management policy 148 such asa storage policy may be stored as metadata in a media agent database 152or in a secondary storage device 108 (e.g., as an archive copy) for usein restore or other information management operations, depending on theembodiment. Information management policies 148 are described furtherbelow. According to certain embodiments, management database 146comprises a relational database (e.g., an SQL database) for trackingmetadata, such as metadata associated with secondary copy operations(e.g., what client computing devices 102 and corresponding subclientdata were protected and where the secondary copies are stored and whichmedia agent 144 performed the storage operation(s)). This and othermetadata may additionally be stored in other locations, such as atsecondary storage computing device 106 or on the secondary storagedevice 108, allowing data recovery without the use of storage manager140 in some cases. Thus, management database 146 may comprise dataneeded to kick off secondary copy operations (e.g., storage policies,schedule policies, etc.), status and reporting information aboutcompleted jobs (e.g., status and error reports on yesterday’s backupjobs), and additional information sufficient to enable restore anddisaster recovery operations (e.g., media agent associations, locationindexing, content indexing, etc.).

Storage manager 140 may include a jobs agent 156, a user interface 158,and a management agent 154, all of which may be implemented asinterconnected software modules or application programs. These aredescribed further below.

Jobs agent 156 in some embodiments initiates, controls, and/or monitorsthe status of some or all information management operations previouslyperformed, currently being performed, or scheduled to be performed bysystem 100. A job is a logical grouping of information managementoperations such as daily storage operations scheduled for a certain setof subclients (e.g., generating incremental block-level backup copies116 at a certain time every day for database files in a certaingeographical location). Thus, jobs agent 156 may access informationmanagement policies 148 (e.g., in management database 146) to determinewhen, where, and how to initiate/control jobs in system 100.

Storage Manager User Interfaces

User interface 158 may include information processing and displaysoftware, such as a graphical user interface (GUI), an applicationprogram interface (API), and/or other interactive interface(s) throughwhich users and system processes can retrieve information about thestatus of information management operations or issue instructions tostorage manager 140 and other components. Via user interface 158, usersmay issue instructions to the components in system 100 regardingperformance of secondary copy and recovery operations. For example, auser may modify a schedule concerning the number of pending secondarycopy operations. As another example, a user may employ the GUI to viewthe status of pending secondary copy jobs or to monitor the status ofcertain components in system 100 (e.g., the amount of capacity left in astorage device). Storage manager 140 may track information that permitsit to select, designate, or otherwise identify content indices,deduplication databases, or similar databases or resources or data setswithin its information management cell (or another cell) to be searchedin response to certain queries. Such queries may be entered by the userby interacting with user interface 158.

Various embodiments of information management system 100 may beconfigured and/or designed to generate user interface data usable forrendering the various interactive user interfaces described. The userinterface data may be used by system 100 and/or by another system,device, and/or software program (for example, a browser program), torender the interactive user interfaces. The interactive user interfacesmay be displayed on, for example, electronic displays (including, forexample, touch-enabled displays), consoles, etc., whetherdirect-connected to storage manager 140 or communicatively coupledremotely, e.g., via an internet connection. The present disclosuredescribes various embodiments of interactive and dynamic userinterfaces, some of which may be generated by user interface agent 158,and which are the result of significant technological development. Theuser interfaces described herein may provide improved human-computerinteractions, allowing for significant cognitive and ergonomicefficiencies and advantages over previous systems, including reducedmental workloads, improved decision-making, and the like. User interface158 may operate in a single integrated view or console (not shown). Theconsole may support a reporting capability for generating a variety ofreports, which may be tailored to a particular aspect of informationmanagement.

User interfaces are not exclusive to storage manager 140 and in someembodiments a user may access information locally from a computingdevice component of system 100. For example, some information pertainingto installed data agents 142 and associated data streams may beavailable from client computing device 102. Likewise, some informationpertaining to media agents 144 and associated data streams may beavailable from secondary storage computing device 106.

Storage Manager Management Agent

Management agent 154 can provide storage manager 140 with the ability tocommunicate with other components within system 100 and/or with otherinformation management cells via network protocols and applicationprogramming interfaces (APIs) including, e.g., HTTP, HTTPS, FTP, REST,virtualization software APIs, cloud service provider APIs, and hostedservice provider APIs, without limitation. Management agent 154 alsoallows multiple information management cells to communicate with oneanother. For example, system 100 in some cases may be one informationmanagement cell in a network of multiple cells adjacent to one anotheror otherwise logically related, e.g., in a WAN or LAN. With thisarrangement, the cells may communicate with one another throughrespective management agents 154. Inter-cell communications andhierarchy is described in greater detail in e.g., U.S. Pat. No.7,343,453.

Information Management Cell

An “information management cell” (or “storage operation cell” or “cell”)may generally include a logical and/or physical grouping of acombination of hardware and software components associated withperforming information management operations on electronic data,typically one storage manager 140 and at least one data agent 142(executing on a client computing device 102) and at least one mediaagent 144 (executing on a secondary storage computing device 106). Forinstance, the components shown in FIG. 1C may together form aninformation management cell. Thus, in some configurations, a system 100may be referred to as an information management cell or a storageoperation cell. A given cell may be identified by the identity of itsstorage manager 140, which is generally responsible for managing thecell.

Multiple cells may be organized hierarchically, so that cells mayinherit properties from hierarchically superior cells or be controlledby other cells in the hierarchy (automatically or otherwise).Alternatively, in some embodiments, cells may inherit or otherwise beassociated with information management policies, preferences,information management operational parameters, or other properties orcharacteristics according to their relative position in a hierarchy ofcells. Cells may also be organized hierarchically according to function,geography, architectural considerations, or other factors useful ordesirable in performing information management operations. For example,a first cell may represent a geographic segment of an enterprise, suchas a Chicago office, and a second cell may represent a differentgeographic segment, such as a New York City office. Other cells mayrepresent departments within a particular office, e.g., human resources,finance, engineering, etc. Where delineated by function, a first cellmay perform one or more first types of information management operations(e.g., one or more first types of secondary copies at a certainfrequency), and a second cell may perform one or more second types ofinformation management operations (e.g., one or more second types ofsecondary copies at a different frequency and under different retentionrules). In general, the hierarchical information is maintained by one ormore storage managers 140 that manage the respective cells (e.g., incorresponding management database(s) 146).

Data Agents

A variety of different applications 110 can operate on a given clientcomputing device 102, including operating systems, file systems,database applications, e-mail applications, and virtual machines, justto name a few. And, as part of the process of creating and restoringsecondary copies 116, the client computing device 102 may be tasked withprocessing and preparing the primary data 112 generated by these variousapplications 110. Moreover, the nature of the processing/preparation candiffer across application types, e.g., due to inherent structural,state, and formatting differences among applications 110 and/or theoperating system of client computing device 102. Each data agent 142 istherefore advantageously configured in some embodiments to assist in theperformance of information management operations based on the type ofdata that is being protected at a client-specific and/orapplication-specific level.

Data agent 142 is a component of information system 100 and is generallydirected by storage manager 140 to participate in creating or restoringsecondary copies 116. Data agent 142 may be a software program (e.g., inthe form of a set of executable binary files) that executes on the sameclient computing device 102 as the associated application 110 that dataagent 142 is configured to protect. Data agent 142 is generallyresponsible for managing, initiating, or otherwise assisting in theperformance of information management operations in reference to itsassociated application(s) 110 and corresponding primary data 112 whichis generated/accessed by the particular application(s) 110. Forinstance, data agent 142 may take part in copying, archiving, migrating,and/or replicating of certain primary data 112 stored in the primarystorage device(s) 104. Data agent 142 may receive control informationfrom storage manager 140, such as commands to transfer copies of dataobjects and/or metadata to one or more media agents 144. Data agent 142also may compress, deduplicate, and encrypt certain primary data 112, aswell as capture application-related metadata before transmitting theprocessed data to media agent 144. Data agent 142 also may receiveinstructions from storage manager 140 to restore (or assist inrestoring) a secondary copy 116 from secondary storage device 108 toprimary storage 104, such that the restored data may be properlyaccessed by application 110 in a suitable format as though it wereprimary data 112.

Each data agent 142 may be specialized for a particular application 110.For instance, different individual data agents 142 may be designed tohandle Microsoft Exchange data, Lotus Notes data, Microsoft Windows filesystem data, Microsoft Active Directory Objects data, SQL Server data,SharePoint data, Oracle database data, SAP database data, virtualmachines and/or associated data, and other types of data. A file systemdata agent, for example, may handle data files and/or other file systeminformation. If a client computing device 102 has two or more types ofdata 112, a specialized data agent 142 may be used for each data type.For example, to backup, migrate, and/or restore all of the data on aMicrosoft Exchange server, the client computing device 102 may use: (1)a Microsoft Exchange Mailbox data agent 142 to back up the Exchangemailboxes; (2) a Microsoft Exchange Database data agent 142 to back upthe Exchange databases; (3) a Microsoft Exchange Public Folder dataagent 142 to back up the Exchange Public Folders; and (4) a MicrosoftWindows File System data agent 142 to back up the file system of clientcomputing device 102. In this example, these specialized data agents 142are treated as four separate data agents 142 even though they operate onthe same client computing device 102. Other examples may include archivemanagement data agents such as a migration archiver or a compliancearchiver, Quick Recovery® agents, and continuous data replicationagents. Application-specific data agents 142 can provide improvedperformance as compared to generic agents. For instance, becauseapplication-specific data agents 142 may only handle data for a singlesoftware application, the design, operation, and performance of the dataagent 142 can be streamlined. The data agent 142 may therefore executefaster and consume less persistent storage and/or operating memory thandata agents designed to generically accommodate multiple differentsoftware applications 110.

Each data agent 142 may be configured to access data and/or metadatastored in the primary storage device(s) 104 associated with data agent142 and its host client computing device 102, and process the dataappropriately. For example, during a secondary copy operation, dataagent 142 may arrange or assemble the data and metadata into one or morefiles having a certain format (e.g., a particular backup or archiveformat) before transferring the file(s) to a media agent 144 or othercomponent. The file(s) may include a list of files or other metadata. Insome embodiments, a data agent 142 may be distributed between clientcomputing device 102 and storage manager 140 (and any other intermediatecomponents) or may be deployed from a remote location or its functionsapproximated by a remote process that performs some or all of thefunctions of data agent 142. In addition, a data agent 142 may performsome functions provided by media agent 144. Other embodiments may employone or more generic data agents 142 that can handle and process datafrom two or more different applications 110, or that can handle andprocess multiple data types, instead of or in addition to usingspecialized data agents 142. For example, one generic data agent 142 maybe used to back up, migrate and restore Microsoft Exchange Mailbox dataand Microsoft Exchange Database data, while another generic data agentmay handle Microsoft Exchange Public Folder data and Microsoft WindowsFile System data.

Media Agents

As noted, off-loading certain responsibilities from client computingdevices 102 to intermediate components such as secondary storagecomputing device(s) 106 and corresponding media agent(s) 144 can providea number of benefits including improved performance of client computingdevice 102, faster and more reliable information management operations,and enhanced scalability. In one example which will be discussed furtherbelow, media agent 144 can act as a local cache of recently-copied dataand/or metadata stored to secondary storage device(s) 108, thusimproving restore capabilities and performance for the cached data.

Media agent 144 is a component of system 100 and is generally directedby storage manager 140 in creating and restoring secondary copies 116.Whereas storage manager 140 generally manages system 100 as a whole,media agent 144 provides a portal to certain secondary storage devices108, such as by having specialized features for communicating with andaccessing certain associated secondary storage device 108. Media agent144 may be a software program (e.g., in the form of a set of executablebinary files) that executes on a secondary storage computing device 106.Media agent 144 generally manages, coordinates, and facilitates thetransmission of data between a data agent 142 (executing on clientcomputing device 102) and secondary storage device(s) 108 associatedwith media agent 144. For instance, other components in the system mayinteract with media agent 144 to gain access to data stored onassociated secondary storage device(s) 108, (e.g., to browse, read,write, modify, delete, or restore data). Moreover, media agents 144 cangenerate and store information relating to characteristics of the storeddata and/or metadata, or can generate and store other types ofinformation that generally provides insight into the contents of thesecondary storage devices 108 - generally referred to as indexing of thestored secondary copies 116. Each media agent 144 may operate on adedicated secondary storage computing device 106, while in otherembodiments a plurality of media agents 144 may operate on the samesecondary storage computing device 106.

A media agent 144 may be associated with a particular secondary storagedevice 108 if that media agent 144 is capable of one or more of: routingand/or storing data to the particular secondary storage device 108;coordinating the routing and/or storing of data to the particularsecondary storage device 108; retrieving data from the particularsecondary storage device 108; coordinating the retrieval of data fromthe particular secondary storage device 108; and modifying and/ordeleting data retrieved from the particular secondary storage device108. Media agent 144 in certain embodiments is physically separate fromthe associated secondary storage device 108. For instance, a media agent144 may operate on a secondary storage computing device 106 in adistinct housing, package, and/or location from the associated secondarystorage device 108. In one example, a media agent 144 operates on afirst server computer and is in communication with a secondary storagedevice(s) 108 operating in a separate rack-mounted RAID-based system.

A media agent 144 associated with a particular secondary storage device108 may instruct secondary storage device 108 to perform an informationmanagement task. For instance, a media agent 144 may instruct a tapelibrary to use a robotic arm or other retrieval means to load or eject acertain storage media, and to subsequently archive, migrate, or retrievedata to or from that media, e.g., for the purpose of restoring data to aclient computing device 102. As another example, a secondary storagedevice 108 may include an array of hard disk drives or solid statedrives organized in a RAID configuration, and media agent 144 mayforward a logical unit number (LUN) and other appropriate information tothe array, which uses the received information to execute the desiredsecondary copy operation. Media agent 144 may communicate with asecondary storage device 108 via a suitable communications link, such asa SCSI or Fibre Channel link.

Each media agent 144 may maintain an associated media agent database152. Media agent database 152 may be stored to a disk or other storagedevice (not shown) that is local to the secondary storage computingdevice 106 on which media agent 144 executes. In other cases, mediaagent database 152 is stored separately from the host secondary storagecomputing device 106. Media agent database 152 can include, among otherthings, a media agent index 153 (see, e.g., FIG. 1C). In some cases,media agent index 153 does not form a part of and is instead separatefrom media agent database 152.

Media agent index 153 (or “index 153”) may be a data structureassociated with the particular media agent 144 that includes informationabout the stored data associated with the particular media agent andwhich may be generated in the course of performing a secondary copyoperation or a restore. Index 153 provides a fast and efficientmechanism for locating/browsing secondary copies 116 or other datastored in secondary storage devices 108 without having to accesssecondary storage device 108 to retrieve the information from there. Forinstance, for each secondary copy 116, index 153 may include metadatasuch as a list of the data objects (e.g., files/subdirectories, databaseobjects, mailbox objects, etc.), a logical path to the secondary copy116 on the corresponding secondary storage device 108, locationinformation (e.g., offsets) indicating where the data objects are storedin the secondary storage device 108, when the data objects were createdor modified, etc. Thus, index 153 includes metadata associated with thesecondary copies 116 that is readily available for use from media agent144. In some embodiments, some or all of the information in index 153may instead or additionally be stored along with secondary copies 116 insecondary storage device 108. In some embodiments, a secondary storagedevice 108 can include sufficient information to enable a “bare metalrestore,” where the operating system and/or software applications of afailed client computing device 102 or another target may beautomatically restored without manually reinstalling individual softwarepackages (including operating systems).

Because index 153 may operate as a cache, it can also be referred to asan “index cache.” In such cases, information stored in index cache 153typically comprises data that reflects certain particulars aboutrelatively recent secondary copy operations. After some triggeringevent, such as after some time elapses or index cache 153 reaches aparticular size, certain portions of index cache 153 may be copied ormigrated to secondary storage device 108, e.g., on a least-recently-usedbasis. This information may be retrieved and uploaded back into indexcache 153 or otherwise restored to media agent 144 to facilitateretrieval of data from the secondary storage device(s) 108. In someembodiments, the cached information may include format orcontainerization information related to archives or other files storedon storage device(s) 108.

In some alternative embodiments media agent 144 generally acts as acoordinator or facilitator of secondary copy operations between clientcomputing devices 102 and secondary storage devices 108, but does notactually write the data to secondary storage device 108. For instance,storage manager 140 (or media agent 144) may instruct a client computingdevice 102 and secondary storage device 108 to communicate with oneanother directly. In such a case, client computing device 102 transmitsdata directly or via one or more intermediary components to secondarystorage device 108 according to the received instructions, and viceversa. Media agent 144 may still receive, process, and/or maintainmetadata related to the secondary copy operations, i.e., may continue tobuild and maintain index 153. In these embodiments, payload data canflow through media agent 144 for the purposes of populating index 153,but not for writing to secondary storage device 108. Media agent 144and/or other components such as storage manager 140 may in some casesincorporate additional functionality, such as data classification,content indexing, deduplication, encryption, compression, and the like.Further details regarding these and other functions are described below.

Distributed, Scalable Architecture

As described, certain functions of system 100 can be distributed amongstvarious physical and/or logical components. For instance, one or more ofstorage manager 140, data agents 142, and media agents 144 may operateon computing devices that are physically separate from one another. Thisarchitecture can provide a number of benefits. For instance, hardwareand software design choices for each distributed component can betargeted to suit its particular function. The secondary computingdevices 106 on which media agents 144 operate can be tailored forinteraction with associated secondary storage devices 108 and providefast index cache operation, among other specific tasks. Similarly,client computing device(s) 102 can be selected to effectively serviceapplications 110 in order to efficiently produce and store primary data112.

Moreover, in some cases, one or more of the individual components ofinformation management system 100 can be distributed to multipleseparate computing devices. As one example, for large file systems wherethe amount of data stored in management database 146 is relativelylarge, database 146 may be migrated to or may otherwise reside on aspecialized database server (e.g., an SQL server) separate from a serverthat implements the other functions of storage manager 140. Thisdistributed configuration can provide added protection because database146 can be protected with standard database utilities (e.g., SQL logshipping or database replication) independent from other functions ofstorage manager 140. Database 146 can be efficiently replicated to aremote site for use in the event of a disaster or other data loss at theprimary site. Or database 146 can be replicated to another computingdevice within the same site, such as to a higher performance machine inthe event that a storage manager host computing device can no longerservice the needs of a growing system 100.

The distributed architecture also provides scalability and efficientcomponent utilization. FIG. 1D shows an embodiment of informationmanagement system 100 including a plurality of client computing devices102 and associated data agents 142 as well as a plurality of secondarystorage computing devices 106 and associated media agents 144.Additional components can be added or subtracted based on the evolvingneeds of system 100. For instance, depending on where bottlenecks areidentified, administrators can add additional client computing devices102, secondary storage computing devices 106, and/or secondary storagedevices 108. Moreover, where multiple fungible components are available,load balancing can be implemented to dynamically address identifiedbottlenecks. As an example, storage manager 140 may dynamically selectwhich media agents 144 and/or secondary storage devices 108 to use forstorage operations based on a processing load analysis of media agents144 and/or secondary storage devices 108, respectively.

Where system 100 includes multiple media agents 144 (see, e.g., FIG.1D), a first media agent 144 may provide failover functionality for asecond failed media agent 144. In addition, media agents 144 can bedynamically selected to provide load balancing. Each client computingdevice 102 can communicate with, among other components, any of themedia agents 144, e.g., as directed by storage manager 140. And eachmedia agent 144 may communicate with, among other components, any ofsecondary storage devices 108, e.g., as directed by storage manager 140.Thus, operations can be routed to secondary storage devices 108 in adynamic and highly flexible manner, to provide load balancing, failover,etc. Further examples of scalable systems capable of dynamic storageoperations, load balancing, and failover are provided in U.S. Pat. No.7,246,207.

While distributing functionality amongst multiple computing devices canhave certain advantages, in other contexts it can be beneficial toconsolidate functionality on the same computing device. In alternativeconfigurations, certain components may reside and execute on the samecomputing device. As such, in other embodiments, one or more of thecomponents shown in FIG. 1C may be implemented on the same computingdevice. In one configuration, a storage manager 140, one or more dataagents 142, and/or one or more media agents 144 are all implemented onthe same computing device. In other embodiments, one or more data agents142 and one or more media agents 144 are implemented on the samecomputing device, while storage manager 140 is implemented on a separatecomputing device, etc. without limitation.

Exemplary Types of Information Management Operations, Including StorageOperations

In order to protect and leverage stored data, system 100 can beconfigured to perform a variety of information management operations,which may also be referred to in some cases as storage managementoperations or storage operations. These operations can generally include(i) data movement operations, (ii) processing and data manipulationoperations, and (iii) analysis, reporting, and management operations.

Data Movement Operations, Including Secondary Copy Operations

Data movement operations are generally storage operations that involvethe copying or migration of data between different locations in system100. For example, data movement operations can include operations inwhich stored data is copied, migrated, or otherwise transferred from oneor more first storage devices to one or more second storage devices,such as from primary storage device(s) 104 to secondary storagedevice(s) 108, from secondary storage device(s) 108 to differentsecondary storage device(s) 108, from secondary storage devices 108 toprimary storage devices 104, or from primary storage device(s) 104 todifferent primary storage device(s) 104, or in some cases within thesame primary storage device 104 such as within a storage array.

Data movement operations can include by way of example, backupoperations, archive operations, information lifecycle managementoperations such as hierarchical storage management operations,replication operations (e.g., continuous data replication), snapshotoperations, deduplication or single-instancing operations, auxiliarycopy operations, disaster-recovery copy operations, and the like. Aswill be discussed, some of these operations do not necessarily createdistinct copies. Nonetheless, some or all of these operations aregenerally referred to as “secondary copy operations” for simplicity,because they involve secondary copies. Data movement also comprisesrestoring secondary copies.

Backup Operations

A backup operation creates a copy of a version of primary data 112 at aparticular point in time (e.g., one or more files or other data units).Each subsequent backup copy 116 (which is a form of secondary copy 116)may be maintained independently of the first. A backup generallyinvolves maintaining a version of the copied primary data 112 as well asbackup copies 116. Further, a backup copy in some embodiments isgenerally stored in a form that is different from the native format,e.g., a backup format. This contrasts to the version in primary data 112which may instead be stored in a format native to the sourceapplication(s) 110. In various cases, backup copies can be stored in aformat in which the data is compressed, encrypted, deduplicated, and/orotherwise modified from the original native application format. Forexample, a backup copy may be stored in a compressed backup format thatfacilitates efficient long-term storage. Backup copies 116 can haverelatively long retention periods as compared to primary data 112, whichis generally highly changeable. Backup copies 116 may be stored on mediawith slower retrieval times than primary storage device 104. Some backupcopies may have shorter retention periods than some other types ofsecondary copies 116, such as archive copies (described below). Backupsmay be stored at an offsite location.

Backup operations can include full backups, differential backups,incremental backups, “synthetic full” backups, and/or creating a“reference copy.” A full backup (or “standard full backup”) in someembodiments is generally a complete image of the data to be protected.However, because full backup copies can consume a relatively largeamount of storage, it can be useful to use a full backup copy as abaseline and only store changes relative to the full backup copyafterwards.

A differential backup operation (or cumulative incremental backupoperation) tracks and stores changes that occurred since the last fullbackup. Differential backups can grow quickly in size, but can restorerelatively efficiently because a restore can be completed in some casesusing only the full backup copy and the latest differential copy.

An incremental backup operation generally tracks and stores changessince the most recent backup copy of any type, which can greatly reducestorage utilization. In some cases, however, restoring can be lengthycompared to full or differential backups because completing a restoreoperation may involve accessing a full backup in addition to multipleincremental backups.

Synthetic full backups generally consolidate data without directlybacking up data from the client computing device. A synthetic fullbackup is created from the most recent full backup (i.e., standard orsynthetic) and subsequent incremental and/or differential backups. Theresulting synthetic full backup is identical to what would have beencreated had the last backup for the subclient been a standard fullbackup. Unlike standard full, incremental, and differential backups,however, a synthetic full backup does not actually transfer data fromprimary storage to the backup media, because it operates as a backupconsolidator. A synthetic full backup extracts the index data of eachparticipating subclient. Using this index data and the previously backedup user data images, it builds new full backup images (e.g., bitmaps),one for each subclient. The new backup images consolidate the index anduser data stored in the related incremental, differential, and previousfull backups into a synthetic backup file that fully represents thesubclient (e.g., via pointers) but does not comprise all its constituentdata.

Any of the above types of backup operations can be at the volume level,file level, or block level. Volume level backup operations generallyinvolve copying of a data volume (e.g., a logical disk or partition) asa whole. In a file-level backup, information management system 100generally tracks changes to individual files and includes copies offiles in the backup copy. For block-level backups, files are broken intoconstituent blocks, and changes are tracked at the block level. Uponrestore, system 100 reassembles the blocks into files in a transparentfashion. Far less data may actually be transferred and copied tosecondary storage devices 108 during a file-level copy than avolume-level copy. Likewise, a block-level copy may transfer less datathan a file-level copy, resulting in faster execution. However,restoring a relatively higher-granularity copy can result in longerrestore times. For instance, when restoring a block-level copy, theprocess of locating and retrieving constituent blocks can sometimes takelonger than restoring file-level backups.

A reference copy may comprise copy(ies) of selected objects from backedup data, typically to help organize data by keeping contextualinformation from multiple sources together, and/or help retain specificdata for a longer period of time, such as for legal hold needs. Areference copy generally maintains data integrity, and when the data isrestored, it may be viewed in the same format as the source data. Insome embodiments, a reference copy is based on a specialized client,individual subclient and associated information management policies(e.g., storage policy, retention policy, etc.) that are administeredwithin system 100.

Archive Operations

Because backup operations generally involve maintaining a version of thecopied primary data 112 and also maintaining backup copies in secondarystorage device(s) 108, they can consume significant storage capacity. Toreduce storage consumption, an archive operation according to certainembodiments creates an archive copy 116 by both copying and removingsource data. Or, seen another way, archive operations can involve movingsome or all of the source data to the archive destination. Thus, datasatisfying criteria for removal (e.g., data of a threshold age or size)may be removed from source storage. The source data may be primary data112 or a secondary copy 116, depending on the situation. As with backupcopies, archive copies can be stored in a format in which the data iscompressed, encrypted, deduplicated, and/or otherwise modified from theformat of the original application or source copy. In addition, archivecopies may be retained for relatively long periods of time (e.g., years)and, in some cases are never deleted. In certain embodiments, archivecopies may be made and kept for extended periods in order to meetcompliance regulations.

Archiving can also serve the purpose of freeing up space in primarystorage device(s) 104 and easing the demand on computational resourceson client computing device 102. Similarly, when a secondary copy 116 isarchived, the archive copy can therefore serve the purpose of freeing upspace in the source secondary storage device(s) 108. Examples of dataarchiving operations are provided in U.S. Pat. No. 7,107,298.

Snapshot Operations

Snapshot operations can provide a relatively lightweight, efficientmechanism for protecting data. From an end-user viewpoint, a snapshotmay be thought of as an “instant” image of primary data 112 at a givenpoint in time, and may include state and/or status information relativeto an application 110 that creates/manages primary data 112. In oneembodiment, a snapshot may generally capture the directory structure ofan object in primary data 112 such as a file or volume or other data setat a particular moment in time and may also preserve file attributes andcontents. A snapshot in some cases is created relatively quickly, e.g.,substantially instantly, using a minimum amount of file space, but maystill function as a conventional file system backup.

A “hardware snapshot” (or “hardware-based snapshot”) operation occurswhere a target storage device (e.g., a primary storage device 104 or asecondary storage device 108) performs the snapshot operation in aself-contained fashion, substantially independently, using hardware,firmware and/or software operating on the storage device itself. Forinstance, the storage device may perform snapshot operations generallywithout intervention or oversight from any of the other components ofthe system 100, e.g., a storage array may generate an “array-created”hardware snapshot and may also manage its storage, integrity,versioning, etc. In this manner, hardware snapshots can off-load othercomponents of system 100 from snapshot processing. An array may receivea request from another component to take a snapshot and then proceed toexecute the “hardware snapshot” operations autonomously, preferablyreporting success to the requesting component.

A “software snapshot” (or “software-based snapshot”) operation, on theother hand, occurs where a component in system 100 (e.g., clientcomputing device 102, etc.) implements a software layer that manages thesnapshot operation via interaction with the target storage device. Forinstance, the component executing the snapshot management software layermay derive a set of pointers and/or data that represents the snapshot.The snapshot management software layer may then transmit the same to thetarget storage device, along with appropriate instructions for writingthe snapshot. One example of a software snapshot product is MicrosoftVolume Snapshot Service (VSS), which is part of the Microsoft Windowsoperating system.

Some types of snapshots do not actually create another physical copy ofall the data as it existed at the particular point in time, but maysimply create pointers that map files and directories to specific memorylocations (e.g., to specific disk blocks) where the data resides as itexisted at the particular point in time. For example, a snapshot copymay include a set of pointers derived from the file system or from anapplication. In some other cases, the snapshot may be created at theblock-level, such that creation of the snapshot occurs without awarenessof the file system. Each pointer points to a respective stored datablock, so that collectively, the set of pointers reflect the storagelocation and state of the data object (e.g., file(s) or volume(s) ordata set(s)) at the point in time when the snapshot copy was created.

An initial snapshot may use only a small amount of disk space needed torecord a mapping or other data structure representing or otherwisetracking the blocks that correspond to the current state of the filesystem. Additional disk space is usually required only when files anddirectories change later on. Furthermore, when files change, typicallyonly the pointers which map to blocks are copied, not the blocksthemselves. For example for “copy-on-write” snapshots, when a blockchanges in primary storage, the block is copied to secondary storage orcached in primary storage before the block is overwritten in primarystorage, and the pointer to that block is changed to reflect the newlocation of that block. The snapshot mapping of file system data mayalso be updated to reflect the changed block(s) at that particular pointin time. In some other cases, a snapshot includes a full physical copyof all or substantially all of the data represented by the snapshot.Further examples of snapshot operations are provided in U.S. Pat. No.7,529,782. A snapshot copy in many cases can be made quickly and withoutsignificantly impacting primary computing resources because largeamounts of data need not be copied or moved. In some embodiments, asnapshot may exist as a virtual file system, parallel to the actual filesystem. Users in some cases gain read-only access to the record of filesand directories of the snapshot. By electing to restore primary data 112from a snapshot taken at a given point in time, users may also returnthe current file system to the state of the file system that existedwhen the snapshot was taken.

Replication Operations

Replication is another type of secondary copy operation. Some types ofsecondary copies 116 periodically capture images of primary data 112 atparticular points in time (e.g., backups, archives, and snapshots).However, it can also be useful for recovery purposes to protect primarydata 112 in a more continuous fashion, by replicating primary data 112substantially as changes occur. In some cases a replication copy can bea mirror copy, for instance, where changes made to primary data 112 aremirrored or substantially immediately copied to another location (e.g.,to secondary storage device(s) 108). By copying each write operation tothe replication copy, two storage systems are kept synchronized orsubstantially synchronized so that they are virtually identical atapproximately the same time. Where entire disk volumes are mirrored,however, mirroring can require significant amount of storage space andutilizes a large amount of processing resources.

According to some embodiments, secondary copy operations are performedon replicated data that represents a recoverable state, or “known goodstate” of a particular application running on the source system. Forinstance, in certain embodiments, known good replication copies may beviewed as copies of primary data 112. This feature allows the system todirectly access, copy, restore, back up, or otherwise manipulate thereplication copies as if they were the “live” primary data 112. This canreduce access time, storage utilization, and impact on sourceapplications 110, among other benefits. Based on known good stateinformation, system 100 can replicate sections of application data thatrepresent a recoverable state rather than rote copying of blocks ofdata. Examples of replication operations (e.g., continuous datareplication) are provided in U.S. Pat. No. 7,617,262.

Deduplication/Single-instancing Operations

Deduplication or single-instance storage is useful to reduce the amountof non-primary data. For instance, some or all of the above-describedsecondary copy operations can involve deduplication in some fashion. Newdata is read, broken down into data portions of a selected granularity(e.g., sub-file level blocks, files, etc.), compared with correspondingportions that are already in secondary storage, and only new/changedportions are stored. Portions that already exist are represented aspointers to the already-stored data. Thus, a deduplicated secondary copy116 may comprise actual data portions copied from primary data 112 andmay further comprise pointers to already-stored data, which is generallymore storage-efficient than a full copy.

In order to streamline the comparison process, system 100 may calculateand/or store signatures (e.g., hashes or cryptographically unique IDs)corresponding to the individual source data portions and compare thesignatures to already-stored data signatures, instead of comparingentire data portions. In some cases, only a single instance of each dataportion is stored, and deduplication operations may therefore bereferred to interchangeably as “single-instancing” operations. Dependingon the implementation, however, deduplication operations can store morethan one instance of certain data portions, yet still significantlyreduce stored-data redundancy. Depending on the embodiment,deduplication portions such as data blocks can be of fixed or variablelength. Using variable length blocks can enhance deduplication byresponding to changes in the data stream, but can involve more complexprocessing. In some cases, system 100 utilizes a technique fordynamically aligning deduplication blocks based on changing content inthe data stream, as described in U.S. Pat. No. 8,364,652.

System 100 can deduplicate in a variety of manners at a variety oflocations. For instance, in some embodiments, system 100 implements“target-side” deduplication by deduplicating data at the media agent 144after being received from data agent 142. In some such cases, mediaagents 144 are generally configured to manage the deduplication process.For instance, one or more of the media agents 144 maintain acorresponding deduplication database that stores deduplicationinformation (e.g., datablock signatures). Examples of such aconfiguration are provided in U.S. Pat. No. 9,020,900. Instead of or incombination with “target-side” deduplication, “source-side” (or“client-side”) deduplication can also be performed, e.g., to reduce theamount of data to be transmitted by data agent 142 to media agent 144.Storage manager 140 may communicate with other components within system100 via network protocols and cloud service provider APIs to facilitatecloud-based deduplication/single instancing, as exemplified in U.S. Pat.No. 8,954,446. Some other deduplication/single instancing techniques aredescribed in U.S. Pat. Pub. No. 2006/0224846 and in U.S. Pat. 9,098,495.

Information Lifecycle Management and Hierarchical Storage Management

In some embodiments, files and other data over their lifetime move frommore expensive quick-access storage to less expensive slower-accessstorage. Operations associated with moving data through various tiers ofstorage are sometimes referred to as information lifecycle management(ILM) operations.

One type of ILM operation is a hierarchical storage management (HSM)operation, which generally automatically moves data between classes ofstorage devices, such as from high-cost to low-cost storage devices. Forinstance, an HSM operation may involve movement of data from primarystorage devices 104 to secondary storage devices 108, or between tiersof secondary storage devices 108. With each tier, the storage devicesmay be progressively cheaper, have relatively slower access/restoretimes, etc. For example, movement of data between tiers may occur asdata becomes less important over time. In some embodiments, an HSMoperation is similar to archiving in that creating an HSM copy may(though not always) involve deleting some of the source data, e.g.,according to one or more criteria related to the source data. Forexample, an HSM copy may include primary data 112 or a secondary copy116 that exceeds a given size threshold or a given age threshold. Often,and unlike some types of archive copies, HSM data that is removed oraged from the source is replaced by a logical reference pointer or stub.The reference pointer or stub can be stored in the primary storagedevice 104 or other source storage device, such as a secondary storagedevice 108 to replace the deleted source data and to point to orotherwise indicate the new location in (another) secondary storagedevice 108.

For example, files are generally moved between higher and lower coststorage depending on how often the files are accessed. When a userrequests access to HSM data that has been removed or migrated, system100 uses the stub to locate the data and may make recovery of the dataappear transparent, even though the HSM data may be stored at a locationdifferent from other source data. In this manner, the data appears tothe user (e.g., in file system browsing windows and the like) as if itstill resides in the source location (e.g., in a primary storage device104). The stub may include metadata associated with the correspondingdata, so that a file system and/or application can provide someinformation about the data object and/or a limited-functionality version(e.g., a preview) of the data object.

An HSM copy may be stored in a format other than the native applicationformat (e.g., compressed, encrypted, deduplicated, and/or otherwisemodified). In some cases, copies which involve the removal of data fromsource storage and the maintenance of stub or other logical referenceinformation on source storage may be referred to generally as “onlinearchive copies.” On the other hand, copies which involve the removal ofdata from source storage without the maintenance of stub or otherlogical reference information on source storage may be referred to as“off-line archive copies.” Examples of HSM and ILM techniques areprovided in U.S. Pat. No. 7,343,453.

Auxiliary Copy Operations

An auxiliary copy is generally a copy of an existing secondary copy 116.For instance, an initial secondary copy 116 may be derived from primarydata 112 or from data residing in secondary storage subsystem 118,whereas an auxiliary copy is generated from the initial secondary copy116. Auxiliary copies provide additional standby copies of data and mayreside on different secondary storage devices 108 than the initialsecondary copies 116. Thus, auxiliary copies can be used for recoverypurposes if initial secondary copies 116 become unavailable. Exemplaryauxiliary copy techniques are described in further detail in U.S. Pat.No. 8,230,195.

Disaster-Recovery Copy Operations

System 100 may also make and retain disaster recovery copies, often assecondary, high-availability disk copies. System 100 may createsecondary copies and store them at disaster recovery locations usingauxiliary copy or replication operations, such as continuous datareplication technologies. Depending on the particular data protectiongoals, disaster recovery locations can be remote from the clientcomputing devices 102 and primary storage devices 104, remote from someor all of the secondary storage devices 108, or both.

Data Manipulation, Including Encryption and Compression

Data manipulation and processing may include encryption and compressionas well as integrity marking and checking, formatting for transmission,formatting for storage, etc. Data may be manipulated “client-side” bydata agent 142 as well as “target-side” by media agent 144 in the courseof creating secondary copy 116, or conversely in the course of restoringdata from secondary to primary.

Encryption Operations

System 100 in some cases is configured to process data (e.g., files orother data objects, primary data 112, secondary copies 116, etc.),according to an appropriate encryption algorithm (e.g., Blowfish,Advanced Encryption Standard (AES), Triple Data Encryption Standard(3-DES), etc.) to limit access and provide data security. System 100 insome cases encrypts the data at the client level, such that clientcomputing devices 102 (e.g., data agents 142) encrypt the data prior totransferring it to other components, e.g., before sending the data tomedia agents 144 during a secondary copy operation. In such cases,client computing device 102 may maintain or have access to an encryptionkey or passphrase for decrypting the data upon restore. Encryption canalso occur when media agent 144 creates auxiliary copies or archivecopies. Encryption may be applied in creating a secondary copy 116 of apreviously unencrypted secondary copy 116, without limitation. Infurther embodiments, secondary storage devices 108 can implementbuilt-in, high performance hardware-based encryption.

Compression Operations

Similar to encryption, system 100 may also or alternatively compressdata in the course of generating a secondary copy 116. Compressionencodes information such that fewer bits are needed to represent theinformation as compared to the original representation. Compressiontechniques are well known in the art. Compression operations may applyone or more data compression algorithms. Compression may be applied increating a secondary copy 116 of a previously uncompressed secondarycopy, e.g., when making archive copies or disaster recovery copies. Theuse of compression may result in metadata that specifies the nature ofthe compression, so that data may be uncompressed on restore ifappropriate.

Data Analysis, Reporting, and Management Operations

Data analysis, reporting, and management operations can differ from datamovement operations in that they do not necessarily involve copying,migration or other transfer of data between different locations in thesystem. For instance, data analysis operations may involve processing(e.g., offline processing) or modification of already stored primarydata 112 and/or secondary copies 116. However, in some embodiments dataanalysis operations are performed in conjunction with data movementoperations. Some data analysis operations include content indexingoperations and classification operations which can be useful inleveraging data under management to enhance search and other features.

Classification Operations / Content Indexing

In some embodiments, information management system 100 analyzes andindexes characteristics, content, and metadata associated with primarydata 112 (“online content indexing”) and/or secondary copies 116(“off-line content indexing”). Content indexing can identify files orother data objects based on content (e.g., user-defined keywords orphrases, other keywords/phrases that are not defined by a user, etc.),and/or metadata (e.g., email metadata such as “to,” “from,” “cc,” “bcc,”attachment name, received time, etc.). Content indexes may be searchedand search results may be restored.

System 100 generally organizes and catalogues the results into a contentindex, which may be stored within media agent database 152, for example.The content index can also include the storage locations of or pointerreferences to indexed data in primary data 112 and/or secondary copies116. Results may also be stored elsewhere in system 100 (e.g., inprimary storage device 104 or in secondary storage device 108). Suchcontent index data provides storage manager 140 or other components withan efficient mechanism for locating primary data 112 and/or secondarycopies 116 of data objects that match particular criteria, thus greatlyincreasing the search speed capability of system 100. For instance,search criteria can be specified by a user through user interface 158 ofstorage manager 140. Moreover, when system 100 analyzes data and/ormetadata in secondary copies 116 to create an “off-line content index,”this operation has no significant impact on the performance of clientcomputing devices 102 and thus does not take a toll on the productionenvironment. Examples of content indexing techniques are provided inU.S. Pat. No. 8,170,995.

One or more components, such as a content index engine, can beconfigured to scan data and/or associated metadata for classificationpurposes to populate a database (or other data structure) ofinformation, which can be referred to as a “data classificationdatabase” or a “metabase.” Depending on the embodiment, the dataclassification database(s) can be organized in a variety of differentways, including centralization, logical sub-divisions, and/or physicalsub-divisions. For instance, one or more data classification databasesmay be associated with different subsystems or tiers within system 100.As an example, there may be a first metabase associated with primarystorage subsystem 117 and a second metabase associated with secondarystorage subsystem 118. In other cases, metabase(s) may be associatedwith individual components, e.g., client computing devices 102 and/ormedia agents 144. In some embodiments, a data classification databasemay reside as one or more data structures within management database146, may be otherwise associated with storage manager 140, and/or mayreside as a separate component. In some cases, metabase(s) may beincluded in separate database(s) and/or on separate storage device(s)from primary data 112 and/or secondary copies 116, such that operationsrelated to the metabase(s) do not significantly impact performance onother components of system 100. In other cases, metabase(s) may bestored along with primary data 112 and/or secondary copies 116. Files orother data objects can be associated with identifiers (e.g., tagentries, etc.) to facilitate searches of stored data objects. Among anumber of other benefits, the metabase can also allow efficient,automatic identification of files or other data objects to associatewith secondary copy or other information management operations. Forinstance, a metabase can dramatically improve the speed with whichsystem 100 can search through and identify data as compared to otherapproaches that involve scanning an entire file system. Examples ofmetabases and data classification operations are provided in U.S. Pat.Nos. 7,734,669 and 7,747,579.

Management and Reporting Operations

Certain embodiments leverage the integrated ubiquitous nature of system100 to provide useful system-wide management and reporting. Operationsmanagement can generally include monitoring and managing the health andperformance of system 100 by, without limitation, performing errortracking, generating granular storage/performance metrics (e.g., jobsuccess/failure information, deduplication efficiency, etc.), generatingstorage modeling and costing information, and the like. As an example,storage manager 140 or another component in system 100 may analyzetraffic patterns and suggest and/or automatically route data to minimizecongestion. In some embodiments, the system can generate predictionsrelating to storage operations or storage operation information. Suchpredictions, which may be based on a trending analysis, may predictvarious network operations or resource usage, such as network trafficlevels, storage media use, use of bandwidth of communication links, useof media agent components, etc. Further examples of traffic analysis,trend analysis, prediction generation, and the like are described inU.S. Pat. No. 7,343,453.

In some configurations having a hierarchy of storage operation cells, amaster storage manager 140 may track the status of subordinate cells,such as the status of jobs, system components, system resources, andother items, by communicating with storage managers 140 (or othercomponents) in the respective storage operation cells. Moreover, themaster storage manager 140 may also track status by receiving periodicstatus updates from the storage managers 140 (or other components) inthe respective cells regarding jobs, system components, systemresources, and other items. In some embodiments, a master storagemanager 140 may store status information and other information regardingits associated storage operation cells and other system information inits management database 146 and/or index 150 (or in another location).The master storage manager 140 or other component may also determinewhether certain storage-related or other criteria are satisfied, and mayperform an action or trigger event (e.g., data migration) in response tothe criteria being satisfied, such as where a storage threshold is metfor a particular volume, or where inadequate protection exists forcertain data. For instance, data from one or more storage operationcells is used to dynamically and automatically mitigate recognizedrisks, and/or to advise users of risks or suggest actions to mitigatethese risks. For example, an information management policy may specifycertain requirements (e.g., that a storage device should maintain acertain amount of free space, that secondary copies should occur at aparticular interval, that data should be aged and migrated to otherstorage after a particular period, that data on a secondary volumeshould always have a certain level of availability and be restorablewithin a given time period, that data on a secondary volume may bemirrored or otherwise migrated to a specified number of other volumes,etc.). If a risk condition or other criterion is triggered, the systemmay notify the user of these conditions and may suggest (orautomatically implement) a mitigation action to address the risk. Forexample, the system may indicate that data from a primary copy 112should be migrated to a secondary storage device 108 to free up space onprimary storage device 104. Examples of the use of risk factors andother triggering criteria are described in U.S. Pat. No. 7,343,453.

In some embodiments, system 100 may also determine whether a metric orother indication satisfies particular storage criteria sufficient toperform an action. For example, a storage policy or other definitionmight indicate that a storage manager 140 should initiate a particularaction if a storage metric or other indication drops below or otherwisefails to satisfy specified criteria such as a threshold of dataprotection. In some embodiments, risk factors may be quantified intocertain measurable service or risk levels. For example, certainapplications and associated data may be considered to be more importantrelative to other data and services. Financial compliance data, forexample, may be of greater importance than marketing materials, etc.Network administrators may assign priority values or “weights” tocertain data and/or applications corresponding to the relativeimportance. The level of compliance of secondary copy operationsspecified for these applications may also be assigned a certain value.Thus, the health, impact, and overall importance of a service may bedetermined, such as by measuring the compliance value and calculatingthe product of the priority value and the compliance value to determinethe “service level” and comparing it to certain operational thresholdsto determine whether it is acceptable. Further examples of the servicelevel determination are provided in U.S. Pat. No. 7,343,453.

System 100 may additionally calculate data costing and data availabilityassociated with information management operation cells. For instance,data received from a cell may be used in conjunction withhardware-related information and other information about system elementsto determine the cost of storage and/or the availability of particulardata. Exemplary information generated could include how fast aparticular department is using up available storage space, how long datawould take to recover over a particular pathway from a particularsecondary storage device, costs over time, etc. Moreover, in someembodiments, such information may be used to determine or predict theoverall cost associated with the storage of certain information. Thecost associated with hosting a certain application may be based, atleast in part, on the type of media on which the data resides, forexample. Storage devices may be assigned to a particular costcategories, for example. Further examples of costing techniques aredescribed in U.S. Pat. No. 7,343,453.

Any of the above types of information (e.g., information related totrending, predictions, job, cell or component status, risk, servicelevel, costing, etc.) can generally be provided to users via userinterface 158 in a single integrated view or console (not shown). Reporttypes may include: scheduling, event management, media management anddata aging. Available reports may also include backup history, dataaging history, auxiliary copy history, job history, library and drive,media in library, restore history, and storage policy, etc., withoutlimitation. Such reports may be specified and created at a certain pointin time as a system analysis, forecasting, or provisioning tool.Integrated reports may also be generated that illustrate storage andperformance metrics, risks and storage costing information. Moreover,users may create their own reports based on specific needs. Userinterface 158 can include an option to graphically depict the variouscomponents in the system using appropriate icons. As one example, userinterface 158 may provide a graphical depiction of primary storagedevices 104, secondary storage devices 108, data agents 142 and/or mediaagents 144, and their relationship to one another in system 100.

In general, the operations management functionality of system 100 canfacilitate planning and decision-making. For example, in someembodiments, a user may view the status of some or all jobs as well asthe status of each component of information management system 100. Usersmay then plan and make decisions based on this data. For instance, auser may view high-level information regarding secondary copy operationsfor system 100, such as job status, component status, resource status(e.g., communication pathways, etc.), and other information. The usermay also drill down or use other means to obtain more detailedinformation regarding a particular component, job, or the like. Furtherexamples are provided in U.S. Pat. No. 7,343,453.

System 100 can also be configured to perform system-wide e-discoveryoperations in some embodiments. In general, e-discovery operationsprovide a unified collection and search capability for data in thesystem, such as data stored in secondary storage devices 108 (e.g.,backups, archives, or other secondary copies 116). For example, system100 may construct and maintain a virtual repository for data stored insystem 100 that is integrated across source applications 110, differentstorage device types, etc. According to some embodiments, e-discoveryutilizes other techniques described herein, such as data classificationand/or content indexing.

Information Management Policies

An information management policy 148 can include a data structure orother information source that specifies a set of parameters (e.g.,criteria and rules) associated with secondary copy and/or otherinformation management operations.

One type of information management policy 148 is a “storage policy.”According to certain embodiments, a storage policy generally comprises adata structure or other information source that defines (or includesinformation sufficient to determine) a set of preferences or othercriteria for performing information management operations. Storagepolicies can include one or more of the following: (1) what data will beassociated with the storage policy, e.g., subclient; (2) a destinationto which the data will be stored; (3) datapath information specifyinghow the data will be communicated to the destination; (4) the type ofsecondary copy operation to be performed; and (5) retention informationspecifying how long the data will be retained at the destination (see,e.g., FIG. 1E). Data associated with a storage policy can be logicallyorganized into subclients, which may represent primary data 112 and/orsecondary copies 116. A subclient may represent static or dynamicassociations of portions of a data volume. Subclients may representmutually exclusive portions. Thus, in certain embodiments, a portion ofdata may be given a label and the association is stored as a staticentity in an index, database or other storage location. Subclients mayalso be used as an effective administrative scheme of organizing dataaccording to data type, department within the enterprise, storagepreferences, or the like. Depending on the configuration, subclients cancorrespond to files, folders, virtual machines, databases, etc. In oneexemplary scenario, an administrator may find it preferable to separatee-mail data from financial data using two different subclients.

A storage policy can define where data is stored by specifying a targetor destination storage device (or group of storage devices). Forinstance, where the secondary storage device 108 includes a group ofdisk libraries, the storage policy may specify a particular disk libraryfor storing the subclients associated with the policy. As anotherexample, where the secondary storage devices 108 include one or moretape libraries, the storage policy may specify a particular tape libraryfor storing the subclients associated with the storage policy, and mayalso specify a drive pool and a tape pool defining a group of tapedrives and a group of tapes, respectively, for use in storing thesubclient data. While information in the storage policy can bestatically assigned in some cases, some or all of the information in thestorage policy can also be dynamically determined based on criteria setforth in the storage policy. For instance, based on such criteria, aparticular destination storage device(s) or other parameter of thestorage policy may be determined based on characteristics associatedwith the data involved in a particular secondary copy operation, deviceavailability (e.g., availability of a secondary storage device 108 or amedia agent 144), network status and conditions (e.g., identifiedbottlenecks), user credentials, and the like.

Datapath information can also be included in the storage policy. Forinstance, the storage policy may specify network pathways and componentsto utilize when moving the data to the destination storage device(s). Insome embodiments, the storage policy specifies one or more media agents144 for conveying data associated with the storage policy between thesource and destination. A storage policy can also specify the type(s) ofassociated operations, such as backup, archive, snapshot, auxiliarycopy, or the like. Furthermore, retention parameters can specify howlong the resulting secondary copies 116 will be kept (e.g., a number ofdays, months, years, etc.), perhaps depending on organizational needsand/or compliance criteria.

When adding a new client computing device 102, administrators canmanually configure information management policies 148 and/or othersettings, e.g., via user interface 158. However, this can be an involvedprocess resulting in delays, and it may be desirable to begin dataprotection operations quickly, without awaiting human intervention.Thus, in some embodiments, system 100 automatically applies a defaultconfiguration to client computing device 102. As one example, when oneor more data agent(s) 142 are installed on a client computing device102, the installation script may register the client computing device102 with storage manager 140, which in turn applies the defaultconfiguration to the new client computing device 102. In this manner,data protection operations can begin substantially immediately. Thedefault configuration can include a default storage policy, for example,and can specify any appropriate information sufficient to begin dataprotection operations. This can include a type of data protectionoperation, scheduling information, a target secondary storage device108, data path information (e.g., a particular media agent 144), and thelike.

Another type of information management policy 148 is a “schedulingpolicy,” which specifies when and how often to perform operations.Scheduling parameters may specify with what frequency (e.g., hourly,weekly, daily, event-based, etc.) or under what triggering conditionssecondary copy or other information management operations are to takeplace. Scheduling policies in some cases are associated with particularcomponents, such as a subclient, client computing device 102, and thelike.

Another type of information management policy 148 is an “audit policy”(or “security policy”), which comprises preferences, rules and/orcriteria that protect sensitive data in system 100. For example, anaudit policy may define “sensitive objects” which are files or dataobjects that contain particular keywords (e.g., “confidential,” or“privileged”) and/or are associated with particular keywords (e.g., inmetadata) or particular flags (e.g., in metadata identifying a documentor email as personal, confidential, etc.). An audit policy may furtherspecify rules for handling sensitive objects. As an example, an auditpolicy may require that a reviewer approve the transfer of any sensitiveobjects to a cloud storage site, and that if approval is denied for aparticular sensitive object, the sensitive object should be transferredto a local primary storage device 104 instead. To facilitate thisapproval, the audit policy may further specify how a secondary storagecomputing device 106 or other system component should notify a reviewerthat a sensitive object is slated for transfer.

Another type of information management policy 148 is a “provisioningpolicy,” which can include preferences, priorities, rules, and/orcriteria that specify how client computing devices 102 (or groupsthereof) may utilize system resources, such as available storage oncloud storage and/or network bandwidth. A provisioning policy specifies,for example, data quotas for particular client computing devices 102(e.g., a number of gigabytes that can be stored monthly, quarterly orannually). Storage manager 140 or other components may enforce theprovisioning policy. For instance, media agents 144 may enforce thepolicy when transferring data to secondary storage devices 108. If aclient computing device 102 exceeds a quota, a budget for the clientcomputing device 102 (or associated department) may be adjustedaccordingly or an alert may trigger.

While the above types of information management policies 148 aredescribed as separate policies, one or more of these can be generallycombined into a single information management policy 148. For instance,a storage policy may also include or otherwise be associated with one ormore scheduling, audit, or provisioning policies or operationalparameters thereof. Moreover, while storage policies are typicallyassociated with moving and storing data, other policies may beassociated with other types of information management operations. Thefollowing is a non-exhaustive list of items that information managementpolicies 148 may specify:

-   schedules or other timing information, e.g., specifying when and/or    how often to perform information management operations;-   the type of secondary copy 116 and/or copy format (e.g., snapshot,    backup, archive, HSM, etc.);-   a location or a class or quality of storage for storing secondary    copies 116 (e.g., one or more particular secondary storage devices    108);-   preferences regarding whether and how to encrypt, compress,    deduplicate, or otherwise modify or transform secondary copies 116;-   which system components and/or network pathways (e.g., preferred    media agents 144) should be used to perform secondary storage    operations;-   resource allocation among different computing devices or other    system components used in performing information management    operations (e.g., bandwidth allocation, available storage capacity,    etc.);-   whether and how to synchronize or otherwise distribute files or    other data objects across multiple computing devices or hosted    services; and-   retention information specifying the length of time primary data 112    and/or secondary copies 116 should be retained, e.g., in a    particular class or tier of storage devices, or within the system    100.

Information management policies 148 can additionally specify or dependon historical or current criteria that may be used to determine whichrules to apply to a particular data object, system component, orinformation management operation, such as:

-   frequency with which primary data 112 or a secondary copy 116 of a    data object or metadata has been or is predicted to be used,    accessed, or modified;-   time-related factors (e.g., aging information such as time since the    creation or modification of a data object);-   deduplication information (e.g., hashes, data blocks, deduplication    block size, deduplication efficiency or other metrics);-   an estimated or historic usage or cost associated with different    components (e.g., with secondary storage devices 108);-   the identity of users, applications 110, client computing devices    102 and/or other computing devices that created, accessed, modified,    or otherwise utilized primary data 112 or secondary copies 116;-   a relative sensitivity (e.g., confidentiality, importance) of a data    object, e.g., as determined by its content and/or metadata;-   the current or historical storage capacity of various storage    devices;-   the current or historical network capacity of network pathways    connecting various components within the storage operation cell;-   access control lists or other security information; and-   the content of a particular data object (e.g., its textual content)    or of metadata associated with the data object.

Exemplary Storage Policy and Secondary Copy Operations

FIG. 1E includes a data flow diagram depicting performance of secondarycopy operations by an embodiment of information management system 100,according to an exemplary storage policy 148A. System 100 includes astorage manager 140, a client computing device 102 having a file systemdata agent 142A and an email data agent 142B operating thereon, aprimary storage device 104, two media agents 144A, 144B, and twosecondary storage devices 108: a disk library 108A and a tape library108B. As shown, primary storage device 104 includes primary data 112A,which is associated with a logical grouping of data associated with afile system (“file system subclient”), and primary data 112B, which is alogical grouping of data associated with email (“email subclient”). Thetechniques described with respect to FIG. 1E can be utilized inconjunction with data that is otherwise organized as well.

As indicated by the dashed box, the second media agent 144B and tapelibrary 108B are “off-site,” and may be remotely located from the othercomponents in system 100 (e.g., in a different city, office building,etc.). Indeed, “off-site” may refer to a magnetic tape located in remotestorage, which must be manually retrieved and loaded into a tape driveto be read. In this manner, information stored on the tape library 108Bmay provide protection in the event of a disaster or other failure atthe main site(s) where data is stored.

The file system subclient 112A in certain embodiments generallycomprises information generated by the file system and/or operatingsystem of client computing device 102, and can include, for example,file system data (e.g., regular files, file tables, mount points, etc.),operating system data (e.g., registries, event logs, etc.), and thelike. The e-mail subclient 112B can include data generated by an e-mailapplication operating on client computing device 102, e.g., mailboxinformation, folder information, emails, attachments, associateddatabase information, and the like. As described above, the subclientscan be logical containers, and the data included in the correspondingprimary data 112A and 112B may or may not be stored contiguously.

The exemplary storage policy 148A includes backup copy preferences orrule set 160, disaster recovery copy preferences or rule set 162, andcompliance copy preferences or rule set 164. Backup copy rule set 160specifies that it is associated with file system subclient 166 and emailsubclient 168. Each of subclients 166 and 168 are associated with theparticular client computing device 102. Backup copy rule set 160 furtherspecifies that the backup operation will be written to disk library 108Aand designates a particular media agent 144A to convey the data to disklibrary 108A. Finally, backup copy rule set 160 specifies that backupcopies created according to rule set 160 are scheduled to be generatedhourly and are to be retained for 30 days. In some other embodiments,scheduling information is not included in storage policy 148A and isinstead specified by a separate scheduling policy.

Disaster recovery copy rule set 162 is associated with the same twosubclients 166 and 168. However, disaster recovery copy rule set 162 isassociated with tape library 108B, unlike backup copy rule set 160.Moreover, disaster recovery copy rule set 162 specifies that a differentmedia agent, namely 144B, will convey data to tape library 108B.Disaster recovery copies created according to rule set 162 will beretained for 60 days and will be generated daily. Disaster recoverycopies generated according to disaster recovery copy rule set 162 canprovide protection in the event of a disaster or other catastrophic dataloss that would affect the backup copy 116A maintained on disk library108A.

Compliance copy rule set 164 is only associated with the email subclient168, and not the file system subclient 166. Compliance copies generatedaccording to compliance copy rule set 164 will therefore not includeprimary data 112A from the file system subclient 166. For instance, theorganization may be under an obligation to store and maintain copies ofemail data for a particular period of time (e.g., 10 years) to complywith state or federal regulations, while similar regulations do notapply to file system data. Compliance copy rule set 164 is associatedwith the same tape library 108B and media agent 144B as disasterrecovery copy rule set 162, although a different storage device or mediaagent could be used in other embodiments. Finally, compliance copy ruleset 164 specifies that the copies it governs will be generated quarterlyand retained for 10 years.

Secondary Copy Jobs

A logical grouping of secondary copy operations governed by a rule setand being initiated at a point in time may be referred to as a“secondary copy job” (and sometimes may be called a “backup job,” eventhough it is not necessarily limited to creating only backup copies).Secondary copy jobs may be initiated on demand as well. Steps 1-9 belowillustrate three secondary copy jobs based on storage policy 148A.

Referring to FIG. 1E, at step 1, storage manager 140 initiates a backupjob according to the backup copy rule set 160, which logically comprisesall the secondary copy operations necessary to effectuate rules 160 instorage policy 148A every hour, including steps 1-4 occurring hourly.For instance, a scheduling service running on storage manager 140accesses backup copy rule set 160 or a separate scheduling policyassociated with client computing device 102 and initiates a backup jobon an hourly basis. Thus, at the scheduled time, storage manager 140sends instructions to client computing device 102 (i.e., to both dataagent 142A and data agent 142B) to begin the backup job.

At step 2, file system data agent 142A and email data agent 142B onclient computing device 102 respond to instructions from storage manager140 by accessing and processing the respective subclient primary data112A and 112B involved in the backup copy operation, which can be foundin primary storage device 104. Because the secondary copy operation is abackup copy operation, the data agent(s) 142A, 142B may format the datainto a backup format or otherwise process the data suitable for a backupcopy.

At step 3, client computing device 102 communicates the processed filesystem data (e.g., using file system data agent 142A) and the processedemail data (e.g., using email data agent 142B) to the first media agent144A according to backup copy rule set 160, as directed by storagemanager 140. Storage manager 140 may further keep a record in managementdatabase 146 of the association between media agent 144A and one or moreof: client computing device 102, file system subclient 112A, file systemdata agent 142A, email subclient 112B, email data agent 142B, and/orbackup copy 116A.

The target media agent 144A receives the data-agent-processed data fromclient computing device 102, and at step 4 generates and conveys backupcopy 116A to disk library 108A to be stored as backup copy 116A, againat the direction of storage manager 140 and according to backup copyrule set 160. Media agent 144A can also update its index 153 to includedata and/or metadata related to backup copy 116A, such as informationindicating where the backup copy 116A resides on disk library 108A,where the email copy resides, where the file system copy resides, dataand metadata for cache retrieval, etc. Storage manager 140 may similarlyupdate its index 150 to include information relating to the secondarycopy operation, such as information relating to the type of operation, aphysical location associated with one or more copies created by theoperation, the time the operation was performed, status informationrelating to the operation, the components involved in the operation, andthe like. In some cases, storage manager 140 may update its index 150 toinclude some or all of the information stored in index 153 of mediaagent 144A. At this point, the backup job may be considered complete.After the 30-day retention period expires, storage manager 140 instructsmedia agent 144A to delete backup copy 116A from disk library 108A andindexes 150 and/or 153 are updated accordingly.

At step 5, storage manager 140 initiates another backup job for adisaster recovery copy according to the disaster recovery rule set 162.This includes steps 5-7 occurring daily for creating disaster recoverycopy 116B. By way of illustrating the scalable aspects and off-loadingprinciples embedded in system 100, disaster recovery copy 116B is basedon backup copy 116A and not on primary data 112A and 112B.

At step 6, based on instructions received from storage manager 140 atstep 5, the specified media agent 144B retrieves the most recent backupcopy 116A from disk library 108A.

At step 7, again at the direction of storage manager 140 and asspecified in disaster recovery copy rule set 162, media agent 144B usesthe retrieved data to create a disaster recovery copy 116B and store itto tape library 108B. In some cases, disaster recovery copy 116B is adirect, mirror copy of backup copy 116A, and remains in the backupformat. In other embodiments, disaster recovery copy 116B may be furthercompressed or encrypted, or may be generated in some other manner, suchas by using primary data 112A and 112B from primary storage device 104as sources. The disaster recovery copy operation is initiated once a dayand disaster recovery copies 116B are deleted after 60 days; indexes 153and/or 150 are updated accordingly when/after each informationmanagement operation is executed and/or completed. The present backupjob may be considered completed.

At step 8, storage manager 140 initiates another backup job according tocompliance rule set 164, which performs steps 8-9 quarterly to createcompliance copy 116C. For instance, storage manager 140 instructs mediaagent 144B to create compliance copy 116C on tape library 108B, asspecified in the compliance copy rule set 164.

At step 9 in the example, compliance copy 116C is generated usingdisaster recovery copy 116B as the source. This is efficient, becausedisaster recovery copy resides on the same secondary storage device andthus no network resources are required to move the data. In otherembodiments, compliance copy 116C is instead generated using primarydata 112B corresponding to the email subclient or using backup copy 116Afrom disk library 108A as source data. As specified in the illustratedexample, compliance copies 116C are created quarterly, and are deletedafter ten years, and indexes 153 and/or 150 are kept up-to-dateaccordingly.

Exemplary Applications of Storage Policies - Information GovernancePolicies and Classification

Again referring to FIG. 1E, storage manager 140 may permit a user tospecify aspects of storage policy 148A. For example, the storage policycan be modified to include information governance policies to define howdata should be managed in order to comply with a certain regulation orbusiness objective. The various policies may be stored, for example, inmanagement database 146. An information governance policy may align withone or more compliance tasks that are imposed by regulations or businessrequirements. Examples of information governance policies might includea Sarbanes-Oxley policy, a HIPAA policy, an electronic discovery(e-discovery) policy, and so on.

Information governance policies allow administrators to obtain differentperspectives on an organization’s online and offline data, without theneed for a dedicated data silo created solely for each differentviewpoint. As described previously, the data storage systems hereinbuild an index that reflects the contents of a distributed data set thatspans numerous clients and storage devices, including both primary dataand secondary copies, and online and offline copies. An organization mayapply multiple information governance policies in a top-down manner overthat unified data set and indexing schema in order to view andmanipulate the data set through different lenses, each of which isadapted to a particular compliance or business goal. Thus, for example,by applying an e-discovery policy and a Sarbanes-Oxley policy, twodifferent groups of users in an organization can conduct two verydifferent analyses of the same underlying physical set of data/copies,which may be distributed throughout the information management system.

An information governance policy may comprise a classification policy,which defines a taxonomy of classification terms or tags relevant to acompliance task and/or business objective. A classification policy mayalso associate a defined tag with a classification rule. Aclassification rule defines a particular combination of criteria, suchas users who have created, accessed or modified a document or dataobject; file or application types; content or metadata keywords; clientsor storage locations; dates of data creation and/or access; reviewstatus or other status within a workflow (e.g., reviewed orun-reviewed); modification times or types of modifications; and/or anyother data attributes in any combination, without limitation. Aclassification rule may also be defined using other classification tagsin the taxonomy. The various criteria used to define a classificationrule may be combined in any suitable fashion, for example, via Booleanoperators, to define a complex classification rule. As an example, ane-discovery classification policy might define a classification tag“privileged” that is associated with documents or data objects that (1)were created or modified by legal department staff, or (2) were sent toor received from outside counsel via email, or (3) contain one of thefollowing keywords: “privileged” or “attorney” or “counsel,” or otherlike terms. Accordingly, all these documents or data objects will beclassified as “privileged.”

One specific type of classification tag, which may be added to an indexat the time of indexing, is an “entity tag.” An entity tag may be, forexample, any content that matches a defined data mask format. Examplesof entity tags might include, e.g., social security numbers (e.g., anynumerical content matching the formatting mask XXX-XX-XXXX), credit cardnumbers (e.g., content having a 13-16 digit string of numbers), SKUnumbers, product numbers, etc. A user may define a classification policyby indicating criteria, parameters or descriptors of the policy via agraphical user interface, such as a form or page with fields to befilled in, pull-down menus or entries allowing one or more of severaloptions to be selected, buttons, sliders, hypertext links or other knownuser interface tools for receiving user input, etc. For example, a usermay define certain entity tags, such as a particular product number orproject ID. In some implementations, the classification policy can beimplemented using cloud-based techniques. For example, the storagedevices may be cloud storage devices, and the storage manager 140 mayexecute cloud service provider API over a network to classify datastored on cloud storage devices.

Restore Operations From Secondary Copies

While not shown in FIG. 1E, at some later point in time, a restoreoperation can be initiated involving one or more of secondary copies116A, 116B, and 116C. A restore operation logically takes a selectedsecondary copy 116, reverses the effects of the secondary copy operationthat created it, and stores the restored data to primary storage where aclient computing device 102 may properly access it as primary data. Amedia agent 144 and an appropriate data agent 142 (e.g., executing onthe client computing device 102) perform the tasks needed to complete arestore operation. For example, data that was encrypted, compressed,and/or deduplicated in the creation of secondary copy 116 will becorrespondingly rehydrated (reversing deduplication), uncompressed, andunencrypted into a format appropriate to primary data. Metadata storedwithin or associated with the secondary copy 116 may be used during therestore operation. In general, restored data should be indistinguishablefrom other primary data 112. Preferably, the restored data has fullyregained the native format that may make it immediately usable byapplication 110.

As one example, a user may manually initiate a restore of backup copy116A, e.g., by interacting with user interface 158 of storage manager140 or with a web-based console with access to system 100. Storagemanager 140 may accesses data in its index 150 and/or managementdatabase 146 (and/or the respective storage policy 148A) associated withthe selected backup copy 116A to identify the appropriate media agent144A and/or secondary storage device 108A where the secondary copyresides. The user may be presented with a representation (e.g., stub,thumbnail, listing, etc.) and metadata about the selected secondarycopy, in order to determine whether this is the appropriate copy to berestored, e.g., date that the original primary data was created. Storagemanager 140 will then instruct media agent 144A and an appropriate dataagent 142 on the target client computing device 102 to restore secondarycopy 116A to primary storage device 104. A media agent may be selectedfor use in the restore operation based on a load balancing algorithm, anavailability based algorithm, or other criteria. The selected mediaagent, e.g., 144A, retrieves secondary copy 116A from disk library 108A.For instance, media agent 144A may access its index 153 to identify alocation of backup copy 116A on disk library 108A, or may accesslocation information residing on disk library 108A itself.

In some cases a backup copy 116A that was recently created or accessed,may be cached to speed up the restore operation. In such a case, mediaagent 144A accesses a cached version of backup copy 116A residing inindex 153, without having to access disk library 108A for some or all ofthe data. Once it has retrieved backup copy 116A, the media agent 144Acommunicates the data to the requesting client computing device 102.Upon receipt, file system data agent 142A and email data agent 142B mayunpack (e.g., restore from a backup format to the native applicationformat) the data in backup copy 116A and restore the unpackaged data toprimary storage device 104. In general, secondary copies 116 may berestored to the same volume or folder in primary storage device 104 fromwhich the secondary copy was derived; to another storage location orclient computing device 102; to shared storage, etc. In some cases, thedata may be restored so that it may be used by an application 110 of adifferent version/vintage from the application that created the originalprimary data 112.

Exemplary Secondary Copy Formatting

The formatting and structure of secondary copies 116 can vary dependingon the embodiment. In some cases, secondary copies 116 are formatted asa series of logical data units or “chunks” (e.g., 512MB, 1GB, 2GB, 4GB,or 8GB chunks). This can facilitate efficient communication and writingto secondary storage devices 108, e.g., according to resourceavailability. For example, a single secondary copy 116 may be written ona chunk-by-chunk basis to one or more secondary storage devices 108. Insome cases, users can select different chunk sizes, e.g., to improvethroughput to tape storage devices. Generally, each chunk can include aheader and a payload. The payload can include files (or other dataunits) or subsets thereof included in the chunk, whereas the chunkheader generally includes metadata relating to the chunk, some or all ofwhich may be derived from the payload. For example, during a secondarycopy operation, media agent 144, storage manager 140, or other componentmay divide files into chunks and generate headers for each chunk byprocessing the files. Headers can include a variety of information suchas file and/or volume identifier(s), offset(s), and/or other informationassociated with the payload data items, a chunk sequence number, etc.Importantly, in addition to being stored with secondary copy 116 onsecondary storage device 108, chunk headers can also be stored to index153 of the associated media agent(s) 144 and/or to index 150 associatedwith storage manager 140. This can be useful for providing fasterprocessing of secondary copies 116 during browsing, restores, or otheroperations. In some cases, once a chunk is successfully transferred to asecondary storage device 108, the secondary storage device 108 returnsan indication of receipt, e.g., to media agent 144 and/or storagemanager 140, which may update their respective indexes 153, 150accordingly. During restore, chunks may be processed (e.g., by mediaagent 144) according to the information in the chunk header toreassemble the files.

Data can also be communicated within system 100 in data channels thatconnect client computing devices 102 to secondary storage devices 108.These data channels can be referred to as “data streams,” and multipledata streams can be employed to parallelize an information managementoperation, improving data transfer rate, among other advantages. Exampledata formatting techniques including techniques involving datastreaming, chunking, and the use of other data structures in creatingsecondary copies are described in U.S. Pat. Nos. 7,315,923, 8,156,086,and 8,578,120.

FIGS. 1F and 1G are diagrams of example data streams 170 and 171,respectively, which may be employed for performing informationmanagement operations. Referring to FIG. 1F, data agent 142 forms datastream 170 from source data associated with a client computing device102 (e.g., primary data 112). Data stream 170 is composed of multiplepairs of stream header 172 and stream data (or stream payload) 174. Datastreams 170 and 171 shown in the illustrated example are for asingle-instanced storage operation, and a stream payload 174 thereforemay include both single-instance (SI) data and/or non-SI data. A streamheader 172 includes metadata about the stream payload 174. This metadatamay include, for example, a length of the stream payload 174, anindication of whether the stream payload 174 is encrypted, an indicationof whether the stream payload 174 is compressed, an archive fileidentifier (ID), an indication of whether the stream payload 174 issingle instanceable, and an indication of whether the stream payload 174is a start of a block of data.

Referring to FIG. 1G, data stream 171 has the stream header 172 andstream payload 174 aligned into multiple data blocks. In this example,the data blocks are of size 64KB. The first two stream header 172 andstream payload 174 pairs comprise a first data block of size 64KB. Thefirst stream header 172 indicates that the length of the succeedingstream payload 174 is 63KB and that it is the start of a data block. Thenext stream header 172 indicates that the succeeding stream payload 174has a length of 1KB and that it is not the start of a new data block.Immediately following stream payload 174 is a pair comprising anidentifier header 176 and identifier data 178. The identifier header 176includes an indication that the succeeding identifier data 178 includesthe identifier for the immediately previous data block. The identifierdata 178 includes the identifier that the data agent 142 generated forthe data block. The data stream 171 also includes other stream header172 and stream payload 174 pairs, which may be for SI data and/or non-SIdata.

FIG. 1H is a diagram illustrating data structures 180 that may be usedto store blocks of SI data and non-SI data on a storage device (e.g.,secondary storage device 108). According to certain embodiments, datastructures 180 do not form part of a native file system of the storagedevice. Data structures 180 include one or more volume folders 182, oneor more chunk folders 184/185 within the volume folder 182, and multiplefiles within chunk folder 184. Each chunk folder 184/185 includes ametadata file 186/187, a metadata index file 188/189, one or morecontainer files 190/191/193, and a container index file 192/194.Metadata file 186/187 stores non-SI data blocks as well as links to SIdata blocks stored in container files. Metadata index file 188/189stores an index to the data in the metadata file 186/187. Containerfiles 190/191/193 store SI data blocks. Container index file 192/194stores an index to container files 190/191/193. Among other things,container index file 192/194 stores an indication of whether acorresponding block in a container file 190/191/193 is referred to by alink in a metadata file 186/187. For example, data block B2 in thecontainer file 190 is referred to by a link in metadata file 187 inchunk folder 185. Accordingly, the corresponding index entry incontainer index file 192 indicates that data block B2 in container file190 is referred to. As another example, data block B1 in container file191 is referred to by a link in metadata file 187, and so thecorresponding index entry in container index file 192 indicates thatthis data block is referred to.

As an example, data structures 180 illustrated in FIG. 1H may have beencreated as a result of separate secondary copy operations involving twoclient computing devices 102. For example, a first secondary copyoperation on a first client computing device 102 could result in thecreation of the first chunk folder 184, and a second secondary copyoperation on a second client computing device 102 could result in thecreation of the second chunk folder 185. Container files 190/191 in thefirst chunk folder 184 would contain the blocks of SI data of the firstclient computing device 102. If the two client computing devices 102have substantially similar data, the second secondary copy operation onthe data of the second client computing device 102 would result in mediaagent 144 storing primarily links to the data blocks of the first clientcomputing device 102 that are already stored in the container files190/191. Accordingly, while a first secondary copy operation may resultin storing nearly all of the data subject to the operation, subsequentsecondary storage operations involving similar data may result insubstantial data storage space savings, because links to already storeddata blocks can be stored instead of additional instances of datablocks.

If the operating system of the secondary storage computing device 106 onwhich media agent 144 operates supports sparse files, then when mediaagent 144 creates container files 190/191/193, it can create them assparse files. A sparse file is a type of file that may include emptyspace (e.g., a sparse file may have real data within it, such as at thebeginning of the file and/or at the end of the file, but may also haveempty space in it that is not storing actual data, such as a contiguousrange of bytes all having a value of zero). Having container files190/191/193 be sparse files allows media agent 144 to free up space incontainer files 190/191/193 when blocks of data in container files190/191/193 no longer need to be stored on the storage devices. In someexamples, media agent 144 creates a new container file 190/191/193 whena container file 190/191/193 either includes 100 blocks of data or whenthe size of the container file 190 exceeds 50 MB. In other examples,media agent 144 creates a new container file 190/191/193 when acontainer file 190/191/193 satisfies other criteria (e.g., it containsfrom approx. 100 to approx. 1000 blocks or when its size exceedsapproximately 50 MB to 1 GB). In some cases, a file on which a secondarycopy operation is performed may comprise a large number of data blocks.For example, a 100 MB file may comprise 400 data blocks of size 256 KB.If such a file is to be stored, its data blocks may span more than onecontainer file, or even more than one chunk folder. As another example,a database file of 20 GB may comprise over 40,000 data blocks of size512 KB. If such a database file is to be stored, its data blocks willlikely span multiple container files, multiple chunk folders, andpotentially multiple volume folders. Restoring such files may requireaccessing multiple container files, chunk folders, and/or volume foldersto obtain the requisite data blocks.

Using Backup Data for Replication and Disaster Recovery (“LiveSynchronization”)

There is an increased demand to off-load resource intensive informationmanagement tasks (e.g., data replication tasks) away from productiondevices (e.g., physical or virtual client computing devices) in order tomaximize production efficiency. At the same time, enterprises expectaccess to readily-available up-to-date recovery copies in the event offailure, with little or no production downtime.

FIG. 2A illustrates a system 200 configured to address these and otherissues by using backup or other secondary copy data to synchronize asource subsystem 201 (e.g., a production site) with a destinationsubsystem 203 (e.g., a failover site). Such a technique can be referredto as “live synchronization” and/or “live synchronization replication.”In the illustrated embodiment, the source client computing devices 202 ainclude one or more virtual machines (or “VMs”) executing on one or morecorresponding VM host computers 205 a, though the source need not bevirtualized. The destination site 203 may be at a location that isremote from the production site 201, or may be located in the same datacenter, without limitation. One or more of the production site 201 anddestination site 203 may reside at data centers at known geographiclocations, or alternatively may operate “in the cloud.”

The synchronization can be achieved by generally applying an ongoingstream of incremental backups from the source subsystem 201 to thedestination subsystem 203, such as according to what can be referred toas an “incremental forever” approach. FIG. 2A illustrates an embodimentof a data flow which may be orchestrated at the direction of one or morestorage managers (not shown). At step 1, the source data agent(s) 242 aand source media agent(s) 244 a work together to write backup or othersecondary copies of the primary data generated by the source clientcomputing devices 202 a into the source secondary storage device(s) 208a. At step 2, the backup/secondary copies are retrieved by the sourcemedia agent(s) 244 a from secondary storage. At step 3, source mediaagent(s) 244 a communicate the backup/secondary copies across a networkto the destination media agent(s) 244 b in destination subsystem 203.

As shown, the data can be copied from source to destination in anincremental fashion, such that only changed blocks are transmitted, andin some cases multiple incremental backups are consolidated at thesource so that only the most current changed blocks are transmitted toand applied at the destination. An example of live synchronization ofvirtual machines using the “incremental forever” approach is found inU.S. Pat. Application No. 62/265,339 entitled “Live Synchronization andManagement of Virtual Machines across Computing and VirtualizationPlatforms and Using Live Synchronization to Support Disaster Recovery.”Moreover, a deduplicated copy can be employed to further reduce networktraffic from source to destination. For instance, the system can utilizethe deduplicated copy techniques described in U.S. Pat. No. 9,239,687,entitled “Systems and Methods for Retaining and Using Data BlockSignatures in Data Protection Operations.”

At step 4, destination media agent(s) 244 b write the receivedbackup/secondary copy data to the destination secondary storagedevice(s) 208 b. At step 5, the synchronization is completed when thedestination media agent(s) and destination data agent(s) 242 b restorethe backup/secondary copy data to the destination client computingdevice(s) 202 b. The destination client computing device(s) 202 b may bekept “warm” awaiting activation in case failure is detected at thesource. This synchronization/replication process can incorporate thetechniques described in U.S. Pat. Application No. 14/721,971, entitled“Replication Using Deduplicated Secondary Copy Data.”

Where the incremental backups are applied on a frequent, on-going basis,the synchronized copies can be viewed as mirror or replication copies.Moreover, by applying the incremental backups to the destination site203 using backup or other secondary copy data, the production site 201is not burdened with the synchronization operations. Because thedestination site 203 can be maintained in a synchronized “warm” state,the downtime for switching over from the production site 201 to thedestination site 203 is substantially less than with a typical restorefrom secondary storage. Thus, the production site 201 may flexibly andefficiently fail over, with minimal downtime and with relativelyup-to-date data, to a destination site 203, such as a cloud-basedfailover site. The destination site 203 can later be reversesynchronized back to the production site 201, such as after repairs havebeen implemented or after the failure has passed.

Integrating With the Cloud Using File System Protocols

Given the ubiquity of cloud computing, it can be increasingly useful toprovide data protection and other information management services in ascalable, transparent, and highly plug-able fashion. FIG. 2B illustratesan information management system 200 having an architecture thatprovides such advantages, and incorporates use of a standard file systemprotocol between primary and secondary storage subsystems 217, 218. Asshown, the use of the network file system (NFS) protocol (or any anotherappropriate file system protocol such as that of the Common InternetFile System (CIFS)) allows data agent 242 to be moved from the primarystorage subsystem 217 to the secondary storage subsystem 218. Forinstance, as indicated by the dashed box 206 around data agent 242 andmedia agent 244, data agent 242 can co-reside with media agent 244 onthe same server (e.g., a secondary storage computing device such ascomponent 106), or in some other location in secondary storage subsystem218.

Where NFS is used, for example, secondary storage subsystem 218allocates an NFS network path to the client computing device 202 or toone or more target applications 210 running on client computing device202. During a backup or other secondary copy operation, the clientcomputing device 202 mounts the designated NFS path and writes data tothat NFS path. The NFS path may be obtained from NFS path data 215stored locally at the client computing device 202, and which may be acopy of or otherwise derived from NFS path data 219 stored in thesecondary storage subsystem 218.

Write requests issued by client computing device(s) 202 are received bydata agent 242 in secondary storage subsystem 218, which translates therequests and works in conjunction with media agent 244 to process andwrite data to a secondary storage device(s) 208, thereby creating abackup or other secondary copy. Storage manager 240 can include apseudo-client manager 217, which coordinates the process by, among otherthings, communicating information relating to client computing device202 and application 210 (e.g., application type, client computing deviceidentifier, etc.) to data agent 242, obtaining appropriate NFS path datafrom the data agent 242 (e.g., NFS path information), and deliveringsuch data to client computing device 202.

Conversely, during a restore or recovery operation client computingdevice 202 reads from the designated NFS network path, and the readrequest is translated by data agent 242. The data agent 242 then workswith media agent 244 to retrieve, re-process (e.g., re-hydrate,decompress, decrypt), and forward the requested data to client computingdevice 202 using NFS.

By moving specialized software associated with system 200 such as dataagent 242 off the client computing devices 202, the architectureeffectively decouples the client computing devices 202 from theinstalled components of system 200, improving both scalability andplug-ability of system 200. Indeed, the secondary storage subsystem 218in such environments can be treated simply as a read/write NFS targetfor primary storage subsystem 217, without the need for informationmanagement software to be installed on client computing devices 202. Asone example, an enterprise implementing a cloud production computingenvironment can add VM client computing devices 202 without installingand configuring specialized information management software on theseVMs. Rather, backups and restores are achieved transparently, where thenew VMs simply write to and read from the designated NFS path. Anexample of integrating with the cloud using file system protocols orso-called “infinite backup” using NFS share is found in U.S. Pat.Application No. 62/294,920, entitled “Data Protection Operations Basedon Network Path Information.” Examples of improved data restorationscenarios based on network-path information, including using storedbackups effectively as primary data sources, may be found in U.S. Pat.Application No. 62/297,057, entitled “Data Restoration Operations Basedon Network Path Information.”

Highly Scalable Managed Data Pool Architecture

Enterprises are seeing explosive data growth in recent years, often fromvarious applications running in geographically distributed locations.FIG. 2C shows a block diagram of an example of a highly scalable,managed data pool architecture useful in accommodating such data growth.The illustrated system 200, which may be referred to as a “web-scale”architecture according to certain embodiments, can be readilyincorporated into both open compute/storage and common-cloudarchitectures.

The illustrated system 200 includes a grid 245 of media agents 244logically organized into a control tier 231 and a secondary or storagetier 233. Media agents assigned to the storage tier 233 can beconfigured to manage a secondary storage pool 208 as a deduplicationstore, and be configured to receive client write and read requests fromthe primary storage subsystem 217, and direct those requests to thesecondary tier 233 for servicing. For instance, media agents CMA1-CMA3in the control tier 231 maintain and consult one or more deduplicationdatabases 247, which can include deduplication information (e.g., datablock hashes, data block links, file containers for deduplicated files,etc.) sufficient to read deduplicated files from secondary storage pool208 and write deduplicated files to secondary storage pool 208. Forinstance, system 200 can incorporate any of the deduplication systemsand methods shown and described in U.S. Pat. No. 9,020,900, entitled“Distributed Deduplicated Storage System,” and U.S. Pat. Pub. No.2014/0201170, entitled “High Availability Distributed DeduplicatedStorage System.”

Media agents SMA1-SMA6 assigned to the secondary tier 233 receive writeand read requests from media agents CMA1-CMA3 in control tier 231, andaccess secondary storage pool 208 to service those requests. Mediaagents CMA1-CMA3 in control tier 231 can also communicate with secondarystorage pool 208, and may execute read and write requests themselves(e.g., in response to requests from other control media agentsCMA1-CMA3) in addition to issuing requests to media agents in secondarytier 233. Moreover, while shown as separate from the secondary storagepool 208, deduplication database(s) 247 can in some cases reside instorage devices in secondary storage pool 208.

As shown, each of the media agents 244 (e.g., CMA1-CMA3, SMA1-SMA6,etc.) in grid 245 can be allocated a corresponding dedicated partition251A-251I, respectively, in secondary storage pool 208. Each partition251 can include a first portion 253 containing data associated with(e.g., stored by) media agent 244 corresponding to the respectivepartition 251. System 200 can also implement a desired level ofreplication, thereby providing redundancy in the event of a failure of amedia agent 244 in grid 245. Along these lines, each partition 251 canfurther include a second portion 255 storing one or more replicationcopies of the data associated with one or more other media agents 244 inthe grid.

System 200 can also be configured to allow for seamless addition ofmedia agents 244 to grid 245 via automatic configuration. As oneexample, a storage manager (not shown) or other appropriate componentmay determine that it is appropriate to add an additional node tocontrol tier 231, and perform some or all of the following: (i) assessthe capabilities of a newly added or otherwise available computingdevice as satisfying a minimum criteria to be configured as or hosting amedia agent in control tier 231; (ii) confirm that a sufficient amountof the appropriate type of storage exists to support an additional nodein control tier 231 (e.g., enough disk drive capacity exists in storagepool 208 to support an additional deduplication database 247); (iii)install appropriate media agent software on the computing device andconfigure the computing device according to a pre-determined template;(iv) establish a partition 251 in the storage pool 208 dedicated to thenewly established media agent 244; and (v) build any appropriate datastructures (e.g., an instance of deduplication database 247). An exampleof highly scalable managed data pool architecture or so-called web-scalearchitecture for storage and data management is found in U.S. Pat.Application No. 62/273,286 entitled “Redundant and Robust DistributedDeduplication Data Storage System.”

The embodiments and components thereof disclosed in FIGS. 2A, 2B, and2C, as well as those in FIGS. 1A-1H, may be implemented in anycombination and permutation to satisfy data storage management andinformation management needs at one or more locations and/or datacenters.

Rapid Restore

As described above, reducing the delay associated with restoring primarydata can improve the efficiency of the information management system 100and improve the user experience. For example, the delay can be reducedby implementing a staging area or cache to temporarily store primarydata in a native format before the primary data is converted intosecondary copies in a secondary format and stored in a secondary storagedevice. If a request to restore primary data is received while theprimary data is stored in the staging area or cache, the primary datacan simply be transmitted to the requesting device without any need toconvert the primary data from one format to another (e.g., from asecondary format to a native format).

FIG. 3 is a block diagram illustrating some portions of a system 300 forrapidly restoring primary data, according to an embodiment. Asillustrated in FIG. 3 , the system 300 may include one or more clientcomputing devices 110, media agents 144A-C, and one or more secondarystorage devices 108.

The media agents 144A-C may each include one or more high speed drives310A-C, one or more low speed drives 320A-C, a snapshot manager 330A-C,a file scanner 340A-C, and a stub creator 350A-C. The high speeddrive(s) 310A-C may be storage devices that have faster read and/orwrite times than the low speed drive(s) 320A-C. For example, the highspeed drive(s) 310A-C can be flash drives, solid state drives, and/orthe like. The low speed drive(s) 320A-C can be electromechanical drives(serial attached small computer system interface (SCSI) (SAS) drives,serial AT attachment (SATA) drives, etc.), tape drives, cloud computingdrives (e.g., drives accessible via a network), and/or the like.

The high speed drive(s) 310A-C may provide computing resources forrunning a first type of file system. The first type of file system maybe a clustered file system formed by the high speed drive(s) 310A-C ofone or more of the media agents 144A-C. As an example, the first type offile system may be configured as an erasure code cluster that canwithstand the loss of 1 of the media agents 144A-C. Client computingdevices 110 can interact with the first type of file system via thenetwork file system (NFS) protocol, via the common Internet file system(CIFS) protocol, via the representational state transfer (REST)protocol, and/or the like.

The low speed drive(s) 320A-C may provide computing resources forrunning a second type of file system. The second type of file system maybe a clustered file system formed by the low speed drive(s) 320A-C ofone or more of the media agents 144A-C. The first type of file systemand the second type of file system can interact with each other to allowprimary data (e.g., files, data objects, etc.) in a native format and/orsecondary copies in a secondary format to be transferred between thefile systems. The two types of file systems may be logically organizedin a hierarchical manner, where the first type of file system isconsidered the highest tier, the portion of the second type of filesystem at which primary data in a native format is stored is consideredthe second highest tier, and the portion of the second type of filesystem at which secondary copies in a secondary format are stored isconsidered the third highest tier.

In an embodiment, the higher the tier, the lower the amount of timerequired by the client computing devices 110 to access the data storedtherein. For example, primary data in the native format stored in thehighest tier may be accessed by a client computing device 110 withextremely good read speeds (e.g., less than a microsecond per byte, lessthan a millisecond per byte, etc.). Primary data in the native formatstored in the second highest tier may be accessed by a client computingdevice 110 with very good read speeds (e.g., less than a millisecond perbyte, less than half a second per byte, etc.). Secondary copies in thesecondary format stored in the third highest tier may be accessed by aclient computing device 110 with good read speeds (e.g., less than halfa second per byte, less than a second per byte, etc.). As described ingreater detail, the difference in read speeds between the differenttiers may be due to the type of format in which the data resides, thespeed of the storage device on which the data is stored, the manner inwhich the requested data is identified and accessed, and/or the like.

The staging area or cache described herein may reside on one or more ofthe high speed drives 310A-C and/or one or more of the low speed drives320A-C. For example, the high speed drive(s) 310A-C may providecomputing resources for a first type of cache that is configured tostore primary data in a native format and/or stubs referencing primarydata and/or secondary copies stored in the low speed drive(s) 320A-C.Thus, the first type of cache may be implemented in the first type offile system. The low speed drive(s) 320A-C may provide computingresources for a second type of cache that is configured to store primarydata in a native format and secondary copies in a secondary format.Thus, the second type of cache may be implemented in the second type offile system.

In general, primary data (or secondary copies generated therefrom)received from a client computing device 110 can transition between thedifferent caches over time. For example, a client computing device 110can provide primary data in a native format to a media agent 144A-C,which stores the primary data in the native format in one or more highspeed drives 310A-C. After a certain amount of time has passed (e.g., asdefined by a storage policy managed by the storage manager 140), themedia agent 144A-C can move the primary data in the native format fromthe high speed drive(s) 310A-C to one or more low speed drives 320A-C.The operations performed to move the primary data are described ingreater detail below. After another amount of time has passed (e.g., asdefined by the storage policy), the media agent 144A-C can convert theprimary data in the native format into secondary copies in a secondaryformat, storing the secondary copies in one or more low speed drives320A-C. After another amount of time has passed (e.g., as defined by thestorage policy), the media agent 144A-C can move the secondary copies inthe secondary format to one or more secondary storage devices 108 forstorage.

When primary data (or a portion thereof) is moved from the high speeddrive(s) 310A-C to the low speed drive(s) 320A-C, a snapshot of theprimary data originally stored on the high speed drive(s) 310A-C can betaken and the primary data can be replaced with stubs that reference thenew storage location of the primary data or a portion thereof. Inparticular, one or more of the snapshot managers 330A-C can capture asnapshot of the primary data in the native format. Before, during,and/or after the snapshot manager 330A-C captures the snapshot, thesnapshot manager 330A-C can instruct one or more of the file scanners340A-C to determine which files, if any, that comprise the primary datahave changed since a previous snapshot was captured. The snapshotmanager 330A-C can use the information provided by the file scanner340A-C to move the changed files from the high speed drive(s) 310A-C tothe low speed drive(s) 320A-C. The snapshot manager 330A-C can alsoinstruct one or more of the stub creators 350A-C to create stubs forsome or all of the files that comprise the primary data, where the stubof a file will reference a storage location of a most recent version ofthe file. Once created, the snapshot manager 330A-C can store the stubsin the high speed drive(s) 310A-C. Thus, when a client computing device110 requests one or more files that have been moved to the low speeddrive(s) 320A-C, the media agent 144A-C can access the stub(s)corresponding to the requested file(s) stored in the high speed drive(s)310A-C to determine the location of the requested file(s). Once thelocation is determined, the media agent 144 can retrieve the requestedfile(s) from the low speed drive(s) 320A-C and transmit the files to theclient computing device 110. Because the files stored in the low speeddrive(s) 320A-C are still in the native format at this stage, the mediaagent 144 may not need to perform any format conversions, therebyspeeding up the file retrieval process.

While FIG. 3 depicts the system 300 as including three media agents144A-C, this is not meant to be limiting. The system 300 can include anynumber of media agents 144 in communication with the client computingdevices 110 and the secondary storage device(s) 108.

FIG. 4 illustrates a block diagram showing the operations performed tomove primary data between the different tiers. As illustrated in FIG. 4, the client computing device 110 may store primary data (e.g., a fileF1) in a native format at (1). At a specific time (e.g., when a userrequest is received, as defined by a storage policy, etc.), the clientcomputing device 110 can request that a secondary copy operation beperformed on the file F1. As a result, the client computing device 110may transmit the file F1 to the media agent 144 or the media agent 144may retrieve the file F1 from the client computing device 110.

The media agent 144 may initially store the file F1 in one or more highspeed drives 310 (e.g., in the first type of file system). Thus, thefile F1 may be stored in a native format on the high speed drive(s) 310at (2). After another period of time (e.g., as defined by the storagepolicy), the media agent 144 can move the file F1 from the first type offile system to the second type of file system (e.g., from the high speeddrive(s) 310 to one or more of the low speed drive(s) 320). Thus, thefile F1 can be stored in a native format on the low speed drive(s) 320at (3).

After another period of time (e.g., as defined by the storage policy),the media agent 144 can convert the file F1 from the native format intoa secondary copy format. The media agent 144 may stored the convertedfile F1 in the same location on the low speed drive(s) 320 or on adifferent location on the low speed drive(s) 320. Thus, the file F1 canbe stored in a secondary copy format on the low speed drive(s) 320 at(4). At some later time (e.g., as defined by the storage policy), themedia agent 144 can move the file F1 in the secondary copy format to oneor more of the secondary storage devices 108, which can be local to thesystem 300 or located remotely from the system 300 and accessible via anetwork.

Alternatively, the file F1 can be directly moved from the highest tierto the third highest tier. For example, the media agent 144 can convertthe file F1 from the native format to a secondary copy format, and movethe file F1 from the high speed drive(s) 310 to the low speed drive(s)320.

FIG. 5 illustrates a block diagram showing the operations performed toenable rapid restore of primary data and/or secondary copies. Asillustrated in FIG. 5 , a client computing device 110 can store files F1and F2, which may be primary data in a native format. The files F1 andF2 may be generated by a single application running on the clientcomputing device 110. Alternatively, the files F1 and F2 may begenerated by multiple applications running on the client computingdevice 110. While FIG. 5 is described with respect to files F1 and F2,this is not meant to be limiting. The same operations can be performedfor any number of files.

In response to a user request or a storage policy, the client computingdevice 110 can store files F1 and F2 in cache at (1). For example, theclient computing device 110 can store files F1 and F2 in the nativeformat in one or more high speed drives 310. The media agent 144 maycreate a staging directory in the cache (e.g., in the high speeddrive(s) 310) that is specific to the client computing device 110 and inwhich the files F1 and F2 can be stored. Thus, the high speed drive(s)310 may include multiple staging directories, with each stagingdirectory being associated with a particular client computing device110. Within the staging directory associated with a particular clientcomputing device 110, the media agent 144 can create multiplesub-directories, with each sub-directory being specific to a particularapplication running on the client computing device 110 associated withthe staging directory. Alternatively, each staging directory can bespecific to a particular application running on a particular clientcomputing device 110. Thus, the media agent 144 can create multiplestaging directories associated with a particular client computing device110, where each staging directory associated with a particular clientcomputing device 110 is associated with a different application runningon the particular client computing device 110. Accordingly, if the mediaagent 144 receives a particular file associated with a first applicationrunning on a first client computing device 110, the media agent 144 canstore the file in the staging directory associated with the first clientcomputing device 110 and the first application or in the stagingdirectory associated with the first client computing device 110 and inthe sub-directory of the staging directory associated with the firstapplication. Here, files F1 and F2 may be stored in the same stagingdirectory and/or sub-directory if the files F1 and F2 are generated bythe same application. Otherwise, the files F1 and F2 may be stored indifferent staging directories and/or sub-directories if the files F1 andF2 are generated by different applications.

As part of the storage, the client computing device 110 may optionallydelete files F1 and F2 from local memory. If the client computing device110 later requests a restore of files F1 and F2, the media agent 144 cansimply retrieve files F1 and F2 from the high speed drive(s) 310 andtransmit the files F1 and F2 to the client computing device 110. Noconversion of the files F1 and F2 from one format to another may berequired.

The storage policy may define that snapshots should be taken of the highspeed drive(s) 310 at periodic intervals, with primary data stored inthe high speed drive(s) 310 being replaced with stubs. Thus, after sometime (e.g., as defined and scheduled by a storage policy), the snapshotmanager 330 can take a snapshot of the high speed drive(s) 310 cache at(2A). The snapshot may be a file level snapshot as opposed to a volumelevel snapshot. The snapshot may also be specific to a particular clientcomputing device 110 and/or an application running on the clientcomputing device 110. Thus, the snapshot manager 330 can take multiplesnapshots at a particular time, with each snapshot being associated witha client computing device 110 and application. Additional details of thestructure of the snapshot are described below.

Before, during, and/or after taking a snapshot of the high speeddrive(s) 310 cache, the snapshot manager 330 can instruct the filescanner 340 to determine which files have changed since a previoussnapshot operation at (2B), and the file scanner 340 can determine thechanged files at (2C). The previous snapshot operation can be the lastsnapshot operation or any other previous snapshot operation. In someembodiments, files are divided or sharded into various file extents, asdescribed in greater detail below. Thus, the file scanner 340 maydetermine the changed file extents in these embodiments. Because files(and/or file extents) previously stored in the high speed drive(s) 310cache may have been replaced with stubs during a previous snapshotoperation, the file scanner 340 can determine whether files (and/or fileextents) currently stored in the high speed drive(s) 310 cache havechanged by accessing the stubs corresponding to the previous snapshotoperation, retrieving the files (and/or file extents) referenced by thestubs, and comparing the retrieved files (and/or file extents) with thefiles (and/or file extents) currently stored in the high speed drive(s)310 cache. In particular, files (and/or file extents) may be labeledwith a particular file name and/or number and/or a particular fileextent name and/or number. The file scanner 340 can compare files(and/or file extents) that have the same file name and/or number and/orthe same file extent name and/or number. If the comparison between twolike files and/or file extents yields a match, then the file scanner 340determines that the file and/or file extent has not changed since aprevious snapshot operation. Similarly, if the comparison between twolike files and/or file extents does not yield a match, then the filescanner 340 determines that the file and/or file extent has changedsince a previous snapshot operation. Once the changed files (and/or fileextents) is determined, the file scanner 340 transmits an indication ofthe changed files (and/or file extents) to the snapshot manager 330 at(3).

The snapshot manager 330 can create, at (4), a directory in one or moreof the low speed drives 320 corresponding to a timestamp of the snapshotthat was just taken. The snapshot manager 330 can then use theinformation provided by the file scanner 340 to identify the changedfiles (and/of file extents), and copy the changed files (and/or fileextents) to the directory in the low speed drive(s) 320 at (5). Thus, aportion of or the entire file F1 and/or a portion of or the entire fileF2 may be copied to the directory in the low speed drive(s) 320.

The snapshot manager 330 can also instruct the stub creator 350 to beginstub creation at (6). As a result, the stub creator 350 can create stubsat (7). For example, a stub can be associated with a particular fileand/or file extent, with the stub identifying a name and/or number ofthe file and/or file extent, extended attributes, and an identificationof a snapshot. The extended attributes can include a product ID (e.g.,the name of a product or computing system to which the file and/or fileextent is being moved), a store ID (e.g., a data store or other datarepository within the product or computing system to which the fileand/or file extent is being moved), and a universally unique identifier(UUID) (e.g., a UUID or path for identifying the storage location of thefile and/or file extent in the data store or other data repository). Theidentification of the snapshot can be a timestamp at which a particularsnapshot was taken, a name of the snapshot, etc. Here, the stub creator350 may create one or more stubs for file F1 and one or more stubs forfile F2. Once created, the stub creator 350 can transmit the stubs tothe snapshot manager 330 at (8).

The snapshot manager 330 can then create a skeleton directory with thestubs in the high speed drive(s) 310 cache at (9). For example, theskeleton directory may be created in the staging directory and/or thesub-directory in which the files F1 and F2 were originally stored, andthe skeleton directory may include the stubs created by the stub creator350. The skeleton directory may be associated with a particular clientcomputing device 110 and/or a particular application running on theclient computing device 110 and may represent a particular snapshot ofthe application, and the structure of the skeleton directory may becreated differently or the same for each combination of client computingdevice 110 and application. In general, the stubs may be organized bysnapshots in the high speed drive(s) 310 cache. Thus, the high speeddrive(s) 310 cache may include multiple skeleton directories, where eachskeleton directory includes a set of stubs corresponding to a particularsnapshot, a particular client computing device 110, and/or a particularapplication running on the client computing device 110.

While FIG. 5 is described with respect to high speed drive(s) 310, lowspeed drive(s) 320, snapshot manager 330, file scanner 340, and stubcreator 350, this is not meant to imply that the operations areperformed by a single media agent 144. Rather, a single media agent144A-C can perform the operations described herein, or one or more ofthe media agents 144A-C can work collectively to perform the operationsdescribed herein. For example, the operations described herein as beingperformed by the snapshot manager 330 can be performed by one or more ofthe snapshot managers 330A-C, the operations described herein as beingperformed by the file scanner 340 can be performed by one or more of thefile scanners 340A-C, and/or the operations described herein as beingperformed by the stub creator 350 can be performed by one or more of thestub creators 350A-C.

In an embodiment, the created stubs can change over time. For example,each stub may include extended attributes that reference a location ofthe stored file and/or file extent. However, when a file or file extentis converted from a native format to a secondary copy format and/ormoved from the low speed drive(s) 320 to one or more secondary storagedevices 108, then the extended attributes of the stub corresponding tothe file or file extent can be updated to reference the new storagelocation of the file or file extent.

In further embodiments, the file scanner 340A-C of one media agent144A-C can identify the changed files and/or file extents from multiplestaged directories and/or sub-directories, and split the changed filesand/or file extents into different work items. The file scanner 340A-Ccan determine how to split the changed files and/or file extents basedon the application that generated the files and/or file extents and/orthe size of the changed files and/or file extents. For example, the filescanner 340A-C can group changed files and/or file extents correspondingto the same application into a single work item. The file scanner 340A-Ccan further split changed files and/or file extents corresponding to thesame application into different work items if combining these changedfiles and/or file extents into one work item would result in the size ofthe combined files and/or file extents exceeding a threshold size. Thus,the file scanner 340A-C may form multiple work items of changed filesand/or file extents, where each work item includes changed files and/orfile extents generated by the same application. The file scanner 340A-Ccan then append or assign a number to each work item. Each stub creator350A-C may then select a work item based on the number appended orassigned to each work item. For example, the stub creators 350A-C canperform a modulo operation to determine which work item to select. As anillustrative example, the stub creators 350A-C can each perform a modulooperation on each work item number. If the modulo operation results in a0, then the stub creator 350A may process the corresponding work item(e.g., generate stubs for the files and/or file extents associated withthe work item). If the modulo operation results in a 1, then the stubcreator 350B may process the corresponding work item (e.g., generatestubs for the files and/or file extents associated with the work item).If the modulo operation results in a 2, then the stub creator 350C mayprocess the corresponding work item (e.g., generate stubs for the filesand/or file extents associated with the work item). In this way, thestub creation load can be distributed across the stub creators 350A-C.

FIG. 6 is a block diagram illustrating additional components of the highspeed drives 310 residing on the media agents 144. As illustrated inFIG. 6 , a high speed drive 310 can include a shard translator 612 and adata reader 614. For example, the high speed drive(s) 310 cache may havea finite size. In some cases, the amount of primary data that the clientcomputing device 110 attempts to dump into the high speed drive(s) 310cache can exceed the size of the cache. Thus, the shard translator 612can divide or shard a file provided by a client computing device 110into one or more file extents that each have a smaller size than thefile itself. As an illustrative example, the shard translator 612 candivide or shard a file into individual file extents having a size of 4MB each.

When a request to restore a file is received from a client computingdevice 110, the shard translator 612 can modify the request to referencea particular file extent and pass the modified request to the datareader 614. The data reader 614 can then retrieve the file extentreferenced by the modified request from the high speed drive(s) 310and/or the low speed drive(s) 320. For example, the data reader 614 canretrieve the referenced file extent from the high speed drive(s) 310 ifa snapshot operation has not yet been performed. The data reader 614 canretrieve the referenced file extent from the low speed drive(s) 320using one or more stubs stored in the high speed drive(s) 310 if asnapshot operation has already been performed.

FIG. 7 illustrates a block diagram showing the operations performed toread a file requested by a client computing device 110. As illustratedin FIG. 7 , the client computing device 110 can submit a read request tothe media agent 144 (e.g., the shard translator 612) requesting file F1at (1). The read request can include an indication of the file beingrequested (e.g., file F1), an offset that indicates a portion of thefile that is being requested (e.g., starting 8 MB into the file F1), anda size of the file being requested (e.g., 256 MB).

The shard translator 612 can receive the read request and modify theread request based on the information included in the read request. Forexample, if the size of file F1 is 256 MB, the shard translator 612 mayhave previously sharded the file F1 into 64 file extents each having asize of 4 MB. An offset of 0 may then refer to the first extent of fileF1 (e.g., file extent F1.1), an offset of 4 MB may then refer to thesecond extent of file F1 (e.g., file extent F1.2), an offset of 8 MB maythen refer to the third extent of file F1 (e.g., file extent F1.3), andso on. Here, because the offset included in the read request is 8 MB,the shard translator 612 may determine that the third extent of file F1is being requested. Thus, the shard translator 612 can modify the readrequest to form a modified read request, where the modified read requestincludes an indication of the file extent being requested (e.g., fileextent F1.3), an offset that indicates a portion of the file extent thatis being requested (e.g., 0 MB in this case), and a size of the filebeing requested (e.g., 256 MB). The shard translator can submit themodified read request to the data reader 614 at (2).

The data reader 614 may identify a stub stored in the high speeddrive(s) 310 corresponding to the requested file extent, and therebydetermine that the file extent is not present on the high speed drive(s)310. Here, the stub may indicate that the file extent is stored on thelow speed drive(s) 320. Thus, the data reader 614 can form a stub readrequest and submit the stub read request to the low speed drive(s) 320at (3). The stub read request may include the same information as themodified read request, optionally including some or all of theinformation included in the identified stub.

Upon receiving the stub read request, the low speed drive(s) 320 canretrieve the requested file extent and transmit the file extent to thedata reader 614. The data reader 614 and/or the shard translator 612 canthen provide the file extent to the client computing device 110.Alternatively, the low speed drive(s) 320 can directly provide therequested file extent to the client computing device 110.

FIG. 8 illustrates a block diagram depicting various stubs and primarydata in a native format stored in the high speed drive(s) 310 and thelow speed drive(s) 320. As illustrated in FIG. 8 , the high speeddrive(s) 310 may include stubs created as a result of four differentsnapshots being taken. For example, a first staging directory and/orsub-directory in the high speed drive(s) 310 may include the followingstubs created as a result of a snapshot 810 taken at time T0: <F1, E1>,<F1, E2>, <F1, E3>, <F2, E1>, <F2, E2>, and <F2, E3>. Thus, a file F1and a file F2 were both generated by a specific application running on aspecific client computing device 110. The file F1 has been sharded intothree extents E1, E2, and E3, and the file F2 has been sharded intothree extents E1, E2, and E3.

The files F1 and F2 may have first been stored on the high speeddrive(s) 310 prior to the snapshot 810 being taken. Thus, the filescanner 340 may determine that each of the file F1 and F2 extents havechanged. Accordingly, the snapshot 810 includes stubs for each of thefile F1 and F2 extents, and the low speed drive(s) 320 include the fileF1 and F2 extents, where the file F1 and F2 extents are in a nativeformat. The file F1 and F2 extents stored in the low speed drive(s) 320may be represented by the following files: <F1, E1>@T0, <F1, E2>@T0,<F1, E3>@T0, <F2, E1>@T0, <F2, E2>@T0, and <F2, E3>@T0, where the storedfile F1 and F2 extents are associated with a timestamp corresponding tothe time that the snapshot 810 was taken.

Some time after the snapshot 810 was taken, a snapshot 812 is taken attime T1. After the snapshot 810 was taken, the client computing device110 may have once again stored files F1 and F2 in the high speeddrive(s) 310. All of the file F1 and F2 extents may be the same as werepreviously stored in the high speed drive(s) 310 except file extent F1,E3. Thus, the file scanner 340 may determine that the file extent F1, E3has changed, and thus the new version of file extent F1, E3 is stored inthe low speed drive(s) 320, represented by <F1, E3>@T1, which indicatesthe timestamp corresponding to the time that the snapshot 812 was taken.Even though only the file extent F1, E3 has changed, the snapshot 812may nonetheless include stubs for each of the file F1 and F2 extents. Asdescribed in greater detail below, however, the stubs corresponding tothe unchanged file F1 and F2 extents may reference the original file F1and F2 extents stored in the low speed drive(s) 320 (e.g., <F1, E1>@T0,<F1, E2>@T0, <F2, E1>@T0, <F2, E2>@T0, and <F2, E3>@T0), whereas thestub corresponding to the changed file F1, E3 extent may reference thenew file F1, E3 extent stored in the low speed drive(s) 320 (e.g., <F1,E3>@T1).

Some time after the snapshot 812 was taken, a snapshot 814 is taken attime T2. After the snapshot 812 was taken, the client computing device110 may have once again stored files F1 and F2 in the high speeddrive(s) 310. All of the file F1 and F2 extents may be the same as werepreviously stored in the high speed drive(s) 310 prior to the snapshot812 being taken except file extent F2, E1. Thus, the file scanner 340may determine that the file extent F2, E1 has changed, and thus the newversion of file extent F2, E1 is stored in the low speed drive(s) 320,represented by <F2, E1>@T2, which indicates the timestamp correspondingto the time that the snapshot 814 was taken. Even though only the fileextent F2, E1 has changed, the snapshot 814 may nonetheless includestubs for each of the file F1 and F2 extents. However, the stubscorresponding to the unchanged file F1 and F2 extents may reference thefile F1 and F2 extents previously stored in the low speed drive(s) 320(e.g., <F1, E1>@T0, <F1, E2>@T0, <F1, E3>@T1, <F2, E2>@T0, and <F2,E3>@T0), whereas the stub corresponding to the changed file F2, E1extent may reference the new file F2, E1 extent stored in the low speeddrive(s) 320 (e.g., <F2, E1>@T2).

Some time after the snapshot 814 was taken, a snapshot 816 is taken attime T3. After the snapshot 814 was taken, the client computing device110 may have once again stored files F1 and F2 in the high speeddrive(s) 310. All of the file F1 and F2 extents may be the same as werepreviously stored in the high speed drive(s) 310 prior to the snapshot814 being taken except file extent F2, E2. Thus, the file scanner 340may determine that the file extent F2, E2 has changed, and thus the newversion of file extent F2, E2 is stored in the low speed drive(s) 320,represented by <F2, E2>@T3, which indicates the timestamp correspondingto the time that the snapshot 816 was taken. Even though only the fileextent F2, E2 has changed, the snapshot 816 may nonetheless includestubs for each of the file F1 and F2 extents. However, the stubscorresponding to the unchanged file F1 and F2 extents may reference thefile F1 and F2 extents previously stored in the low speed drive(s) 320(e.g., <F1, E1>@T0, <F1, E2>@T0, <F1, E3>@T1, <F2, E1>@T2, and <F2,E3>@T0), whereas the stub corresponding to the changed file F2, E2extent may reference the new file F2, E2 extent stored in the low speeddrive(s) 320 (e.g., <F2, E2>@T3).

The snapshots 810, 812, 814, and 816 may be stored in different stagingdirectories and/or sub-directories. Each of the staging directoriesand/or sub-directories, however, may be associated with the same clientcomputing device 110 and application running on the client computingdevice 110.

FIG. 9 illustrates the structure of various snapshots 810, 812, 814, and816. As illustrated in FIG. 9 , the snapshot 810 includes six stubscorresponding to file extents <F1, E1>@T0, <F1, E2>@T0, <F1, E3>@T0,<F2, E1>@T0, <F2, E2>@T0, and <F2, E3>@T0. The stubs may include anidentification of the file extent, an indication of a product ID, anindication of a store ID, an indication of a UUID, and an indication ofa snapshot corresponding to the file extent (e.g., a timestamp of thecorresponding snapshot). Thus, if a client computing device 110 requestsa restoration of the files F1 and F2 as the files existed at time T0,the media agent 144 can use the stubs that comprise the snapshot 810 toidentify the location of the corresponding file F1 and F2 extents,retrieve the corresponding file F1 and F2 extents from the identifiedlocation, and provide the file F1 and F2 extents to the client computingdevice 110. In some embodiments, the shard translator 612 can merge thefile F1 extents to re-form the file F1 and/or can merge the file F2extents to re-form the file F2 before the files F1 and F2 are providedto the client computing device 110 to satisfy the request. As describedherein, the media agent 144 may not need to perform any conversion ofthe files F1 and F2 given that the files F1 and F2 may be stored in thelow speed drive(s) 320 in the native format instead of the secondarycopy format. However, the media agent 144 may convert the files F1 andF2 into the native format if the file F1 and F2 extents are stored inthe low speed drive(s) 320 in the secondary copy format.

Similarly, the snapshot 812 includes six stubs corresponding to fileextents <F1, E1>@T0, <F1, E2>@T0, <F1, E3>@T1, <F2, E1>@T0, <F2, E2>@T0,and <F2, E3>@T0. The stub for file extent F1, E3 may reference the T1version of the file extent F1, E3 rather than the T0 version of the fileextent F1, E3 because the file extent F1, E3 may have changed after thesnapshot 810 was taken and before the snapshot 812 was taken. The stubsmay include an identification of the file extent, an indication of aproduct ID, an indication of a store ID, an indication of a UUID, and anindication of a snapshot corresponding to the file extent (e.g., atimestamp of the corresponding snapshot). Thus, if a client computingdevice 110 requests a restoration of the files F1 and F2 as the filesexisted at time T1, the media agent 144 can use the stubs that comprisethe snapshot 812 to identify the location of the corresponding file F1and F2 extents, retrieve the corresponding file F1 and F2 extents fromthe identified location, and provide the file F1 and F2 extents to theclient computing device 110. In some embodiments, the shard translator612 can merge the file F1 extents to re-form the file F1 and/or canmerge the file F2 extents to re-form the file F2 before the files F1 andF2 are provided to the client computing device 110 to satisfy therequest. As described herein, the media agent 144 may not need toperform any conversion of the files F1 and F2 given that the files F1and F2 may be stored in the low speed drive(s) 320 in the native formatinstead of the secondary copy format. However, the media agent 144 mayconvert the files F1 and F2 into the native format if the file F1 and F2extents are stored in the low speed drive(s) 320 in the secondary copyformat.

The snapshot 814 includes six stubs corresponding to file extents <F1,E1>@T0, <F1, E2>@T0, <F1, E3>@T1, <F2, E1>@T2, <F2, E2>@T0, and <F2,E3>@T0. The stub for file extent F1, E3 may reference the T1 version ofthe file extent F1, E3 rather than the T0 version of the file extent F1,E3 because the file extent F1, E3 may have changed after the snapshot810 was taken and before the snapshot 812 was taken. Similarly, the stubfor file extent F2, E1 may reference the T2 version of the file extentF2, E1 rather than the T0 version of the file extent F2, E1 because thefile extent F2, E1 may have changed after the snapshots 810 and 812 weretaken and before the snapshot 814 was taken. The stubs may include anidentification of the file extent, an indication of a product ID, anindication of a store ID, an indication of a UUID, and an indication ofa snapshot corresponding to the file extent (e.g., a timestamp of thecorresponding snapshot). Thus, if a client computing device 110 requestsa restoration of the files F1 and F2 as the files existed at time T2,the media agent 144 can use the stubs that comprise the snapshot 814 toidentify the location of the corresponding file F1 and F2 extents,retrieve the corresponding file F1 and F2 extents from the identifiedlocation, and provide the file F1 and F2 extents to the client computingdevice 110. In some embodiments, the shard translator 612 can merge thefile F1 extents to re-form the file F1 and/or can merge the file F2extents to re-form the file F2 before the files F1 and F2 are providedto the client computing device 110 to satisfy the request. As describedherein, the media agent 144 may not need to perform any conversion ofthe files F1 and F2 given that the files F1 and F2 may be stored in thelow speed drive(s) 320 in the native format instead of the secondarycopy format. However, the media agent 144 may convert the files F1 andF2 into the native format if the file F1 and F2 extents are stored inthe low speed drive(s) 320 in the secondary copy format.

The snapshot 816 includes six stubs corresponding to file extents <F1,E1>@T0, <F1, E2>@T0, <F1, E3>@T1, <F2, E1>@T2, <F2, E2>@T3, and <F2,E3>@T0. The stub for file extent F1, E3 may reference the T1 version ofthe file extent F1, E3 rather than the T0 version of the file extent F1,E3 because the file extent F1, E3 may have changed after the snapshot810 was taken and before the snapshot 812 was taken. Similarly, the stubfor file extent F2, E1 may reference the T2 version of the file extentF2, E1 rather than the T0 version of the file extent F2, E1 because thefile extent F2, E1 may have changed after the snapshots 810 and 812 weretaken and before the snapshot 814 was taken. In addition, the stub forfile extent F2, E2 may reference the T3 version of the file extent F2,E2 rather than the T0 version of the file extent F2, E2 because the fileextent F2, E2 may have changed after the snapshots 810, 812, and 814were taken and before the snapshot 816 was taken. The stubs may includean identification of the file extent, an indication of a product ID, anindication of a store ID, an indication of a UUID, and an indication ofa snapshot corresponding to the file extent (e.g., a timestamp of thecorresponding snapshot). Thus, if a client computing device 110 requestsa restoration of the files F1 and F2 as the files existed at time T3,the media agent 144 can use the stubs that comprise the snapshot 816 toidentify the location of the corresponding file F1 and F2 extents,retrieve the corresponding file F1 and F2 extents from the identifiedlocation, and provide the file F1 and F2 extents to the client computingdevice 110. In some embodiments, the shard translator 612 can merge thefile F1 extents to re-form the file F1 and/or can merge the file F2extents to re-form the file F2 before the files F1 and F2 are providedto the client computing device 110 to satisfy the request. As describedherein, the media agent 144 may not need to perform any conversion ofthe files F1 and F2 given that the files F1 and F2 may be stored in thelow speed drive(s) 320 in the native format instead of the secondarycopy format. However, the media agent 144 may convert the files F1 andF2 into the native format if the file F1 and F2 extents are stored inthe low speed drive(s) 320 in the secondary copy format.

FIG. 10 illustrates the structure of various snapshots 1010, 1012, and1014 after a file extent is deleted. In an embodiment, file extents maybe stored in the low speed drive(s) 320 as separate files in a nativeformat. A file extent can be referenced by multiple stubs, such as stubsthat comprise different snapshots. When all the snapshots that includestubs referencing a particular file extent are deleted, the file extentcan also be deleted from the low speed drive(s) 320. For example,snapshots may be deleted from the high speed drive(s) 310 on a periodicbasis according to a storage policy.

As illustrated in FIG. 10 , the snapshot 1010 includes six stubscorresponding to file extents <F1, E1>@T0, <F1, E2>@T0, <F1, E3>@T0,<F2, E1>@T0, <F2, E2>@T0, and <F2, E3>@T0. The stubs may include anidentification of the file extent, an indication of a product ID, anindication of a store ID, an indication of a UUID, and an indication ofa snapshot corresponding to the file extent (e.g., a timestamp of thecorresponding snapshot). Thus, if a client computing device 110 requestsa restoration of the files F1 and F2 as the files existed at time T0,the media agent 144 can use the stubs that comprise the snapshot 1010 toidentify the location of the corresponding file F1 and F2 extents,retrieve the corresponding file F1 and F2 extents from the identifiedlocation, and provide the file F1 and F2 extents to the client computingdevice 110. In some embodiments, the shard translator 612 can merge thefile F1 extents to re-form the file F1 and/or can merge the file F2extents to re-form the file F2 before the files F1 and F2 are providedto the client computing device 110 to satisfy the request. As describedherein, the media agent 144 may not need to perform any conversion ofthe files F1 and F2 given that the files F1 and F2 may be stored in thelow speed drive(s) 320 in the native format instead of the secondarycopy format. However, the media agent 144 may convert the files F1 andF2 into the native format if the file F1 and F2 extents are stored inthe low speed drive(s) 320 in the secondary copy format.

Similarly, the snapshot 1012 includes six stubs corresponding to fileextents <F1, E1>@T0, <F1, E2>@T0, <F1, E3>@T1, <F2, E1>@T0, <F2, E2>@T0,and <F2, E3>@T0. The stub for file extent F1, E3 may reference the T1version of the file extent F1, E3 rather than the T0 version of the fileextent F1, E3 because the file extent F1, E3 may have changed after thesnapshot 1010 was taken and before the snapshot 1012 was taken. Thestubs may include an identification of the file extent, an indication ofa product ID, an indication of a store ID, an indication of a UUID, andan indication of a snapshot corresponding to the file extent (e.g., atimestamp of the corresponding snapshot). Thus, if a client computingdevice 110 requests a restoration of the files F1 and F2 as the filesexisted at time T1, the media agent 144 can use the stubs that comprisethe snapshot 1012 to identify the location of the corresponding file F1and F2 extents, retrieve the corresponding file F1 and F2 extents fromthe identified location, and provide the file F1 and F2 extents to theclient computing device 110. In some embodiments, the shard translator612 can merge the file F1 extents to re-form the file F1 and/or canmerge the file F2 extents to re-form the file F2 before the files F1 andF2 are provided to the client computing device 110 to satisfy therequest. As described herein, the media agent 144 may not need toperform any conversion of the files F1 and F2 given that the files F1and F2 may be stored in the low speed drive(s) 320 in the native formatinstead of the secondary copy format. However, the media agent 144 mayconvert the files F1 and F2 into the native format if the file F1 and F2extents are stored in the low speed drive(s) 320 in the secondary copyformat.

The snapshot 1014 includes five stubs corresponding to file extents <F1,E1>@T0, <F1, E2>@T0, <F1, E3>@T1, <F2, E1>@T0, and <F2, E2>@T0. The stubfor file extent F1, E3 may reference the T1 version of the file extentF1, E3 rather than the T0 version of the file extent F1, E3 because thefile extent F1, E3 may have changed after the snapshot 1010 was takenand before the snapshot 1012 was taken. A stub for file extent F2, E3may no longer be present because the file extent F2, E3 may have beendeleted from the low speed drive(s) 320 after the snapshots 1010 and1012 were taken and before the snapshot 1014 was taken. The stubs mayinclude an identification of the file extent, an indication of a productID, an indication of a store ID, an indication of a UUID, and anindication of a snapshot corresponding to the file extent (e.g., atimestamp of the corresponding snapshot). Thus, if a client computingdevice 110 requests a restoration of the files F1 and F2 as the filesexisted at time T2, the media agent 144 can use the stubs that comprisethe snapshot 1014 to identify the location of the corresponding file F1and F2 extents, retrieve the corresponding file F1 and F2 extents fromthe identified location, and provide the file F1 and F2 extents to theclient computing device 110. In some embodiments, the shard translator612 can merge the file F1 extents to re-form the file F1 and/or canmerge the file F2 extents to re-form the file F2 before the files F1 andF2 are provided to the client computing device 110 to satisfy therequest. As described herein, the media agent 144 may not need toperform any conversion of the files F1 and F2 given that the files F1and F2 may be stored in the low speed drive(s) 320 in the native formatinstead of the secondary copy format. However, the media agent 144 mayconvert the files F1 and F2 into the native format if the file F1 and F2extents are stored in the low speed drive(s) 320 in the secondary copyformat

In an embodiment, the snapshot manager 330 may create one or more deletefiles in association with a previous snapshot when the file scanner 340determines that one or more files and/or file extents have changedduring a snapshot operation, where each delete file corresponds to achanged file and/or file extent. As an illustrative example, thesnapshot manager 330 may create a delete file for file extent F1, E3 inassociation with the snapshot 1010 when the snapshot 1012 is beingcreated given that the file extent F1, E3 has changed after the snapshot1010 was taken, and may create a delete file for file extent F2, E3 inassociation with the snapshot 1012 when the snapshot 1014 is beingcreated given that the file extent F2, E3 is deleted after the snapshot1012 was taken. The delete file may reference the previous version ofthe file extent (e.g., the delete files may reference file extent <F1,E3>@T0 and <F2, E3>@T0 in this case).

If the media agent 144 deletes a snapshot, then the media agent 144 maydelete any file extents referenced by delete files associated with thedeleted snapshot given that the file extent is no longer referenced byany active snapshot. As an illustrative example, if the media agent 144deletes the snapshot 1010 from the high speed drive(s) 310, then themedia agent 144 may also delete the file extent <F1, E3>@T0 stored inthe low speed drive(s) 320 given that the file extent <F1, E3>@T0 is nolonger referenced by any active snapshot. If the media agent 144 thendeletes the snapshot 1012 from the high speed drive(s) 310, then themedia agent 144 may also delete the file extent <F2, E3>@T0 stored inthe low speed drive(s) 320 given that the file extent <F2, E3>@T0 is nolonger referenced by any active snapshot.

If the media agent 144 deletes one snapshot before deleting anothersnapshot that was taken before the deleted snapshot, then the mediaagent 144 may move the delete files associated with the deleted snapshotto be associated with the previous and still active snapshot given thatthe file extents referenced by the delete files associated with thedeleted snapshot are still referenced by an active snapshot. As anillustrative example, if the media agent 144 deletes the snapshot 1012from the high speed drive(s) 310 before deleting the snapshot 1010, thenthe media agent 144 may move the delete file corresponding to the fileextent <F2, E3>@T0 to be associated with the snapshot 1010 given thatthe file extent <F2, E3>@T0 is still referenced by snapshot 1010. If themedia agent 144 then deletes the snapshot 1010 from the high speeddrive(s) 310, then the media agent 144 may also delete the file extents<F1, E3>@T0 and <F2, E3>@T0 stored in the low speed drive(s) 320 giventhat these file extents <F1, E3>@T0 and <F2, E3>@T0 are no longerreferenced by any active snapshot.

FIG. 11 depicts some operations of a method 1100 for enabling rapidrestore of primary data and/or secondary copies, according to anembodiment. The method 1100 may be implemented, for example, by a mediaagent, such as one or more of the media agents 144A-C. The method 1100may start at block 1102.

At block 1102, a first file is received from a client computing device.The first file may be primary data in a native format. For example, thefirst file can be part of data dumped by the client computing device 110onto high speed drive(s) 310. The first file may be generated by aspecific application running on the client computing device 110.

At block 1104, the first file is stored in a first drive. For example,the first drive may be one or more of the high speed drive(s) 310. Thefirst file may be stored in the first drive in a native format.

In an embodiment, if the client computing device 110 then requests arestore of the first file, the media agent 144 can simply retrieve thefirst file from the high speed drive(s) 310 and transmit the first fileto the client computing device 110. The media agent 144 may not need toperform any conversion of the first file because the first file isalready stored in the native format. Thus, the high speed drive(s) 310may act as a staging area or cache for rapid restore of the first file.

In some embodiments, the first file may be sharded and stored as fileextents in the first drive. Thus, the media agent 144 may combine thefile extents to re-form the first file before transmitting the firstfile back to the client computing device 110 in response to a request torestore the first file.

At block 1106, a snapshot is taken of at least a portion of the firstdrive. For example, the first file may be stored in a particular stagingdirectory and/or sub-directory in the first drive. The snapshot may betaken of the staging directory and/or sub-directory at which the firstfile is stored.

At block 1108, a determination is made that the first file has changedsince a previous snapshot operation. For example, the determination maybe made that the first file has changed because the first file did notexist in the first drive prior to the snapshot being taken.

In an embodiment, the determination can be performed simultaneously withthe snapshot being taken. In another embodiment, the determination canbe performed before or after the snapshot is taken.

At block 1110, the first file is stored in a native format in a seconddrive. For example, the second drive may have slower read and/or writetimes than the first drive. The first file may be stored in the seconddrive because the determination was made that the first file changed. Ifa determination was made that the first file has not changed since aprevious snapshot operation, then the first file may not be stored inthe second drive because the same version of the first file may alreadyexist on the second drive.

In an embodiment, storing the first file in the native format in thesecond drive may result in a deletion of the first file from the firstdrive. In another embodiment, storing the first file in the nativeformat in the second drive may not immediately result in a deletion ofthe first file from the first drive. For example, the first file mayremain on the first drive until overwritten by the client computingdevice via another data dump.

At block 1112, a stub is created referencing the first file. Forexample, the stub may reference the first file, a product ID, a storeID, a UUID, and a time at which the snapshot was taken. In general, thestub may reference a location at which the first file is stored in thenative format on the second drive.

In an embodiment, the contents of the stub can change over time. Forexample, if the first file is later converted into a secondary copy in asecondary copy format, the extended attributes of the stub may beupdated accordingly (e.g., to reference the new storage location of thefirst file in the secondary copy format). Similarly, if the first fileis later stored in one or more secondary storage devices 108 in asecondary copy format, the extended attributes of the stub may beupdated accordingly (e.g., to reference the new storage location of thefirst file in the secondary copy format).

At block 1114, the stub is stored in the first drive. For example, thestub is included as part of the snapshot, and the snapshot is stored onthe first drive. The first drive may include multiple stored snapshots,and the snapshots can include the same or different stubs.

In an embodiment, if the client computing device 110 then requests arestore of the first file, the media agent 144 can simply identify thestub in the first drive referencing the first file, retrieve the firstfile from the low speed drive(s) 320 based on information included inthe identified stub, and transmit the first file to the client computingdevice 110. The media agent 144 may not need to perform any conversionof the first file because the first file is already stored in the nativeformat. Thus, the low speed drive(s) 320 may act as a staging area orcache for rapid restore of the first file.

While FIG. 11 is described with respect to a first file, this is notmeant to be limiting. As described herein, the media agent 144 can sharda file into multiple file extents. The operations described herein asbeing performed by method 1100 on the first file can also be performedon a file extent as well. After the stub is stored in the first drive,the method 1100 is complete.

FIG. 12 depicts some operations of a method 1200 for rapidly restoringprimary data and/or secondary copies, according to an embodiment. Themethod 1200 may be implemented, for example, by a media agent, such asone or more of the media agents 144A-C. The method 1200 may start atblock 1202.

At block 1202, a request is received from a client computing device torestore a first file. The first file may be stored on in the high speeddrive(s) 310, in the low speed drive(s) 320, or in the secondary storagedevice(s) 108. The first file may have previously been provided to themedia agent 144 by the client computing device 110.

At block 1204, a stub stored in a first drive is identified ascorresponding to the first file. For example, the stub may identify aparticular file (e.g., the first file), a version of the first file(e.g., based on a timestamp at which a snapshot of the first file wastaken), and extended attributes associated with the first file. Thefirst drive may be one or more of the high speed drive(s) 310.

Alternatively, a stub corresponding to the first file may not be presentin the first drive. Rather, the first file itself may be present in thefirst drive. In this situation, the media agent 144 can simply retrievethe first file from the first drive and transmit the first file to theclient computing device 110. The media agent 144 may not need to performany conversion of the first file because the first file is alreadystored in the native format. Thus, the high speed drive(s) 310 may actas a staging area or cache for rapid restore of the first file.

At block 1206, the first file is retrieved from a second drive based oninformation included in the stub. For example, the second drive may haveslower read and/or write times than the first drive. The first file maybe stored in the second drive after a snapshot operation is performed.The information included in the stub may include extended attributesthat reference a storage location of the first file.

In an embodiment, the first file is stored in the second drive in anative format. Thus, the media agent 144 may not need to perform anyconversion of the first file. In another embodiment, the first file isstored in the second drive in a secondary copy format. Thus, the mediaagent 144 may need to perform a conversion of the first file from thesecondary copy format into a native format.

At block 1208, the retrieved first file is transmitted to the clientcomputing device. The first file can be transmitted to the clientcomputing device directly from the second type of file system running onthe second drive or via the first type of file system running on thefirst drive.

While FIG. 12 is described with respect to a first file, this is notmeant to be limiting. As described herein, the media agent 144 can sharda file into multiple file extents. The operations described herein asbeing performed by method 1200 on the first file can also be performedon a file extent as well. After the first file is transmitted to theclient computing device 110, the method 1200 is complete.

In regard to the figures described herein, other embodiments arepossible, such that the above-recited components, steps, blocks,operations, and/or messages/requests/queries/instructions aredifferently arranged, sequenced, sub-divided, organized, and/orcombined. In some embodiments, a different component may initiate orexecute a given operation. For example, in some embodiments, a dataagent 142 can perform some or all of the operations described herein asbeing performed by the media agent 144. For example, the data agent 142may maintain a staging area or cache, such as the cache formed by thehigh speed drive(s) 310, and the media agent 144 may maintain a cacheformed by the low speed drive(s) 320.

EXAMPLE EMBODIMENTS

Some example enumerated embodiments are recited in this section in theform of methods, systems, and non-transitory computer-readable media,without limitation.

One aspect of the disclosure provides a networked information managementsystem. The networked information management system comprises a clientcomputing device having one or more first hardware processors, whereinthe client computing device executes an application that generated afirst file. The networked information management system furthercomprises one or more computing devices in communication with the clientcomputing device, wherein the one or more computing devices comprise afirst drive and a second drive, wherein the one or more computingdevices each have one or more second hardware processors, wherein theone or more computing devices are configured with computer-executableinstructions that, when executed, cause the one or more computingdevices to: process a request received from the client computing deviceto restore a version of a first file that existed at a first time;identify a snapshot stored in the first drive that is associated withthe first time and that includes a stub corresponding to the first file,wherein the stub references a storage location of the first file in thesecond drive; retrieve the first file from the storage location in thesecond drive based on the identified stub, wherein the first file isstored in the storage location in the second drive in a native format;transmit the first file retrieved from the storage location to theclient computing device; process a request received from the clientcomputing device to restore a version of the first file that existed ata second time before the first time; identify a second snapshot storedin the first drive that is associated with the second time and thatincludes a second stub corresponding to the first file, wherein thesecond stub references a second storage location of the first file inthe second drive; retrieve the first file from the second storagelocation in the second drive based on the identified second stub,wherein the first file is stored in the second storage location in thesecond drive in a secondary copy format; convert the first fileretrieved from the second storage location from the secondary copyformat to the native format; and transmit the converted first file tothe client computing device.

The networked information management system of the preceding paragraphcan include any sub-combination of the following features: where thecomputer-executable instructions, when executed, further cause the oneor more computing devices to shard the version of the first file thatexisted at the first time into a first file extent and a second fileextent; where the computer-executable instructions, when executed,further cause the one or more computing devices to: determine that therequest received from the client computing device corresponds to thesecond file extent, identify the snapshot stored in the first drive thatincludes the stub corresponding to the second file extent, retrieve thesecond file extent from the second drive based on the identified stub,and transmit the retrieved second file extent to the client computingdevice; where the computer-executable instructions, when executed,further cause the one or more computing devices to: receive an updatedversion of the first file, store the updated version of the first filein the first drive, determine that the first file has changed since aprevious snapshot operation, store the updated version of the first filein the second drive, create a second stub corresponding to the updatedversion of the first file, and create a skeleton directory in the firstdrive, wherein the skeleton directory comprises the second stub; wherethe computer-executable instructions, when executed, further cause theone or more computing devices to delete the updated version of the firstfile from the first drive; where the computer-executable instructions,when executed, further cause the one or more computing devices totransmit the first file retrieved from the storage location to theclient computing device without performing a conversion operation toconvert the first file into the native format; where the snapshot isstored in the first drive in association with the client computingdevice and the application executed by the client computing device;where the stub comprises an indication of the first file, a product IDidentifying a name of a computing system that stores the version of thefirst file that existed at the first time, a store ID identifying thatthe second drive stores the version of the first file that existed atthe first time, a universally unique identifier (UUID) identifying thestorage location of the version of the first file that existed at thefirst time in the second drive, and an indication of a time that thesnapshot was taken; where the first drive forms at least a portion of afirst type of file system, and wherein the second drive forms at least aportion of a second type of file system; and where read times of thesecond drive are slower than read times of the first drive.

Another aspect of the disclosure provides a computer-implemented methodcomprising: receiving, by one or more computing devices comprising afirst drive and a second drive, a request from a client computing deviceto restore a version of a first file that existed at a first time,wherein the first file is previously provided by the client computingdevice to the one or more computing devices, and wherein the first fileis generated by an application executed by the client computing device;identifying a snapshot stored in the first drive that is associated withthe first time and that includes a stub corresponding to the first file,wherein the stub references a storage location of the first file in thesecond drive; retrieving the first file from the storage location in thesecond drive based on the identified stub, wherein the first file isstored in the storage location in the second drive in a native format;transmitting the first file retrieved from the storage location to theclient computing device; processing a request received from the clientcomputing device to restore a version of the first file that existed ata second time before the first time; identifying a second snapshotstored in the first drive that is associated with the second time andthat includes a second stub corresponding to the first file, wherein thesecond stub references a second storage location of the first file inthe second drive; retrieving the first file from the second storagelocation in the second drive based on the identified second stub,wherein the first file is stored in the second storage location in thesecond drive in a secondary copy format; converting the first fileretrieved from the second storage location from the secondary copyformat to the native format; and transmitting the converted first fileto the client computing device.

The computer-implemented method of the preceding paragraph can includeany sub-combination of the following features: where thecomputer-implemented method further comprises sharding the version ofthe first file that existed at the first time into a first file extentand a second file extent; where the computer-implemented method furthercomprises: determining that the request received from the clientcomputing device corresponds to the second file extent, identifying thesnapshot stored in the first drive that includes the stub correspondingto the second file extent, retrieving the second file extent from thesecond drive based on the identified stub, and transmitting theretrieved second file extent to the client computing device; where thecomputer-implemented method further comprises: receiving an updatedversion of the first file, storing the updated version of the first filein the first drive, determining that the first file has changed since aprevious snapshot operation, storing the updated version of the firstfile in the second drive, creating a second stub corresponding to theupdated version of the first file, and creating a skeleton directory inthe first drive, wherein the skeleton directory comprises the secondstub; where transmitting the retrieved first file to the clientcomputing device further comprises transmitting the first file retrievedfrom the storage location to the client computing device withoutperforming a conversion operation to convert the first file into thenative format; where the snapshot is stored in the first drive inassociation with the client computing device and the applicationexecuted by the client computing device; where the stub comprises anindication of the first file, a product ID identifying a name of acomputing system that stores the version of the first file that existedat the first time, a store ID identifying that the second drive storesthe version of the first file that existed at the first time, auniversally unique identifier (UUID) identifying the storage location ofthe version of the first file that existed at the first time in thesecond drive, and an indication of a time that the snapshot was taken;where the first drive forms at least a portion of a first type of filesystem, and wherein the second drive forms at least a portion of asecond type of file system; and where read times of the second drive areslower than read times of the first drive.

Another aspect of the disclosure provides a non-transitorycomputer-readable medium storing instructions, which when executed byone or more computing devices comprising a first drive and a seconddrive, cause the one or more computing devices to perform a methodcomprising: receiving a request from a client computing device torestore a version of a first file that existed at a first time, whereinthe first file is previously provided by the client computing device tothe one or more computing devices, and wherein the first file isgenerated by an application executed by the client computing device;identifying a snapshot stored in the first drive that is associated withthe first time and that includes a stub corresponding to the first file,wherein the stub references a storage location of the first file in thesecond drive; retrieving the first file from the storage location in thesecond drive based on the identified stub, wherein the first file isstored in the storage location in the second drive in a native format;transmitting the first file retrieved from the storage location to theclient computing device; processing a request received from the clientcomputing device to restore a version of the first file that existed ata second time before the first time; identifying a second snapshotstored in the first drive that is associated with the second time andthat includes a second stub corresponding to the first file, wherein thesecond stub references a second storage location of the first file inthe second drive; retrieving the first file from the second storagelocation in the second drive based on the identified second stub,wherein the first file is stored in the second storage location in thesecond drive in a secondary copy format; converting the first fileretrieved from the second storage location from the secondary copyformat to the native format; and transmitting the converted first fileto the client computing device.

In other embodiments, a system or systems may operate according to oneor more of the methods and/or computer-readable media recited in thepreceding paragraphs. In yet other embodiments, a method or methods mayoperate according to one or more of the systems and/or computer-readablemedia recited in the preceding paragraphs. In yet more embodiments, acomputer-readable medium or media, excluding transitory propagatingsignals, may cause one or more computing devices having one or moreprocessors and non-transitory computer-readable memory to operateaccording to one or more of the systems and/or methods recited in thepreceding paragraphs.

Terminology

Conditional language, such as, among others, “can,” “could,” “might,” or“may,” unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements and/or steps are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or without userinput or prompting, whether these features, elements and/or steps areincluded or are to be performed in any particular embodiment.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense, i.e., in the sense of “including, but notlimited to.” As used herein, the terms “connected,” “coupled,” or anyvariant thereof means any connection or coupling, either direct orindirect, between two or more elements; the coupling or connectionbetween the elements can be physical, logical, or a combination thereof.Additionally, the words “herein,” “above,” “below,” and words of similarimport, when used in this application, refer to this application as awhole and not to any particular portions of this application. Where thecontext permits, words using the singular or plural number may alsoinclude the plural or singular number respectively. The word “or” inreference to a list of two or more items, covers all of the followinginterpretations of the word: any one of the items in the list, all ofthe items in the list, and any combination of the items in the list.Likewise the term “and/or” in reference to a list of two or more items,covers all of the following interpretations of the word: any one of theitems in the list, all of the items in the list, and any combination ofthe items in the list.

In some embodiments, certain operations, acts, events, or functions ofany of the algorithms described herein can be performed in a differentsequence, can be added, merged, or left out altogether (e.g., not allare necessary for the practice of the algorithms). In certainembodiments, operations, acts, functions, or events can be performedconcurrently, e.g., through multi-threaded processing, interruptprocessing, or multiple processors or processor cores or on otherparallel architectures, rather than sequentially.

Systems and modules described herein may comprise software, firmware,hardware, or any combination(s) of software, firmware, or hardwaresuitable for the purposes described. Software and other modules mayreside and execute on servers, workstations, personal computers,computerized tablets, PDAs, and other computing devices suitable for thepurposes described herein. Software and other modules may be accessiblevia local computer memory, via a network, via a browser, or via othermeans suitable for the purposes described herein. Data structuresdescribed herein may comprise computer files, variables, programmingarrays, programming structures, or any electronic information storageschemes or methods, or any combinations thereof, suitable for thepurposes described herein. User interface elements described herein maycomprise elements from graphical user interfaces, interactive voiceresponse, command line interfaces, and other suitable interfaces.

Further, processing of the various components of the illustrated systemscan be distributed across multiple machines, networks, and othercomputing resources. Two or more components of a system can be combinedinto fewer components. Various components of the illustrated systems canbe implemented in one or more virtual machines, rather than in dedicatedcomputer hardware systems and/or computing devices. Likewise, the datarepositories shown can represent physical and/or logical data storage,including, e.g., storage area networks or other distributed storagesystems. Moreover, in some embodiments the connections between thecomponents shown represent possible paths of data flow, rather thanactual connections between hardware. While some examples of possibleconnections are shown, any of the subset of the components shown cancommunicate with any other subset of components in variousimplementations.

Embodiments are also described above with reference to flow chartillustrations and/or block diagrams of methods, apparatus (systems) andcomputer program products. Each block of the flow chart illustrationsand/or block diagrams, and combinations of blocks in the flow chartillustrations and/or block diagrams, may be implemented by computerprogram instructions. Such instructions may be provided to a processorof a general purpose computer, special purpose computer,specially-equipped computer (e.g., comprising a high-performancedatabase server, a graphics subsystem, etc.) or other programmable dataprocessing apparatus to produce a machine, such that the instructions,which execute via the processor(s) of the computer or other programmabledata processing apparatus, create means for implementing the actsspecified in the flow chart and/or block diagram block or blocks. Thesecomputer program instructions may also be stored in a non-transitorycomputer-readable memory that can direct a computer or otherprogrammable data processing apparatus to operate in a particularmanner, such that the instructions stored in the computer-readablememory produce an article of manufacture including instruction meanswhich implement the acts specified in the flow chart and/or blockdiagram block or blocks. The computer program instructions may also beloaded to a computing device or other programmable data processingapparatus to cause operations to be performed on the computing device orother programmable apparatus to produce a computer implemented processsuch that the instructions which execute on the computing device orother programmable apparatus provide steps for implementing the actsspecified in the flow chart and/or block diagram block or blocks.

Any patents and applications and other references noted above, includingany that may be listed in accompanying filing papers, are incorporatedherein by reference. Aspects of one or more embodiments can be modified,if necessary, to employ the systems, functions, and concepts of thevarious references described above. These and other changes can be madein light of the above Detailed Description. While the above descriptiondescribes certain examples, and describes the best mode contemplated, nomatter how detailed the above appears in text, different embodiments canbe practiced in many ways. Details of the system may vary considerablyin its specific implementation. As noted above, particular terminologyused when describing certain features should not be taken to imply thatthe terminology is being redefined herein to be restricted to anyspecific characteristics, features with which that terminology isassociated. In general, the terms used in the following claims shouldnot be construed to limit the scope the specific examples disclosed inthe specification, unless the above Detailed Description sectionexplicitly defines such terms. Accordingly, the actual scope encompassesnot only the disclosed examples, but also all equivalent ways ofpracticing or implementing the claims.

To reduce the number of claims, certain aspects are presented below incertain claim forms, but the applicant contemplates other aspects in anynumber of claim forms. For example, while only one aspect may be recitedas a means-plus-function claim under 35 U.S.C. sec. 112(f) (AIA), otheraspects may likewise be embodied as a means-plus-function claim, or inother forms, such as being embodied in a computer-readable medium. Anyclaims intended to be treated under 35 U.S.C. §112(f) will begin withthe words “means for,” but use of the term “for” in any other context isnot intended to invoke treatment under 35 U.S.C. §112(f). Accordingly,the applicant reserves the right to pursue additional claims afterfiling this application, in either this application or in a continuingapplication.

What is claimed is:
 1. A system comprising: a first computing device incommunication with a client computing device that comprises one or morehardware processors, wherein the client computing device is configuredto execute an application that generates a first data file in a nativeformat, wherein the native format is associated with the application; afirst drive that comprises one or more first data storage devices; and asecond drive that comprises one or more second data storage devices,wherein the first drive is configured to read the first data file fromone or more of the one or more first data storage devices faster thanthe second drive is configured to read the first data file from one ormore of the one or more second data storage devices; and wherein thefirst computing device comprises one or more hardware processors, andfurther comprises the first drive and the second drive, and wherein thefirst computing device is configured with computer-executableinstructions that, when executed, cause the first computing device to:store the first data file in the native format in the first drive, andafter a first amount of time, move the first data file in the nativeformat from the first drive to the second drive, and after a secondamount of time, (a) convert the first data file from the native formatinto one or more secondary copies that are in a secondary copy format,wherein the secondary copy format is distinct from the native format,and (b) store the one or more secondary copies, in the secondary copyformat, in the second drive; wherein a request for the first data fileis served from one of the first drive and the second drive, depending ona timing of the request compared to the first amount of time and thesecond amount of time.
 2. The system of claim 1, wherein thecomputer-executable instructions, when executed, further cause the firstcomputing device to: based on a first request for the first data file,wherein the first request is received before the first data file hasbeen moved to the second drive, transmit the first data file in thenative format from the first drive.
 3. The system of claim 1, whereinthe computer-executable instructions, when executed, further cause thefirst computing device to: based on a second request for the first datafile, wherein the second request is received after the first data filehas been moved to the second drive and before the first data file hasbeen converted into the one or more secondary copies, transmit the firstdata file in the native format from the second drive.
 4. The system ofclaim 1, wherein the computer-executable instructions, when executed,further cause the first computing device to: based on a third requestfor the first data file, wherein the third request is received after thefirst data file has been converted into the one or more secondarycopies, (A) restore the one or more secondary copies from the secondarycopy format into the first data file in the native format, and (B)transmit the first data file in the native format from the second drive.5. The system of claim 1, wherein the computer-executable instructions,when executed, further cause the first computing device to: take asnapshot of the first drive; based on determining that the first datafile has changed since a preceding snapshot, store the first data filein the native format at the second drive; and at the first drive, storea stub that references the first data file at the second drive.
 6. Thesystem of claim 1, wherein the first drive is configured in the systemas a faster storage tier than the second drive.
 7. The system of claim1, wherein the first drive is configured in the system as a fasterstorage tier than a first portion of the second drive that stores thefirst data file in the native format, and wherein a second portion ofthe second drive that stores the one or more secondary copies in thesecondary copy format is configured in the system as a slower storagetier than the first portion of the second drive.
 8. The system of claim1, wherein a storage manager that executes on a third computing deviceis configured to manage one or more storage policies that define thefirst amount of time and the second amount of time, wherein the thirdcomputing device is distinct from one or more of: the client computingdevice and the first computing device, and wherein the third computingdevice comprises one or more hardware processors.
 9. The system of claim1, wherein the first drive is configured to execute a first file systemand wherein the second drive is configured to execute a second filesystem, which is distinct from, and of a different type than, the firstfile system.
 10. The system of claim 1, wherein the computer-executableinstructions, when executed, further cause the first computing deviceto: receive an updated version of the first data file, store the updatedversion of the first data file in the first drive, determine that thefirst data file has changed since a preceding snapshot operation, storethe updated version of the first data file in the second drive, in thenative format; and store, at the first drive, a stub that references theupdated version of the first data file stored at the second drive.
 11. Acomputer-implemented method performed by a system, wherein the systemcomprises: a first computing device in communication with a clientcomputing device that is configured to execute an application thatgenerates a first data file in a native format, wherein the nativeformat is associated with the application; wherein the system furthercomprises a first drive that comprises one or more first data storagedevices; and wherein the system further comprises a second drive thatcomprises one or more second data storage devices, wherein the firstdrive is configured to read the first data file from one or more of theone or more first data storage devices faster than the second drive isconfigured to read the first data file from one or more of the one ormore second data storage devices; and wherein the method comprises:storing the first data file in the native format in the first drive;after a first amount of time, moving the first data file in the nativeformat from the first drive to the second drive; and after a secondamount of time, (a) converting the first data file from the nativeformat into one or more secondary copies that are in a secondary copyformat, wherein the secondary copy format is distinct from the nativeformat, and (b) storing the one or more secondary copies, in thesecondary copy format, in the second drive; and serving a request forthe first data file from one of the first drive and the second drive,depending on a timing of the request compared to the first amount oftime and the second amount of time.
 12. The computer-implemented methodof claim 11, further comprising: based on a first request for the firstdata file, wherein the first request is received before the first datafile has been moved to the second drive, transmitting the first datafile in the native format from the first drive.
 13. Thecomputer-implemented method of claim 11, further comprising: based on asecond request for the first data file, wherein the second request isreceived after the first data file has been moved to the second driveand before the first data file has been converted into the one or moresecondary copies, transmitting the first data file in the native formatfrom the second drive.
 14. The computer-implemented method of claim 11,further comprising: based on a third request for the first data file,wherein the third request is received after the first data file has beenconverted into the one or more secondary copies, (A) restoring the oneor more secondary copies from the secondary copy format into the firstdata file in the native format, and (B) transmitting the first data filein the native format from the second drive.
 15. The computer-implementedmethod of claim 11, further comprising: taking a snapshot of the firstdrive; based on determining that the first data file has changed since apreceding snapshot, storing the first data file in the native format atthe second drive; at the first drive, storing a stub that references thefirst data file at the second drive.
 16. The computer-implemented methodof claim 11, wherein the first drive is configured in the system as afaster storage tier than the second drive.
 17. The computer-implementedmethod of claim 11, wherein the first drive is configured in the systemas a faster storage tier than a first portion of the second drive thatstores the first data file in the native format, and wherein a secondportion of the second drive that stores the one or more secondary copiesin the secondary copy format is configured in the system as a slowerstorage tier than the first portion of the second drive.
 18. Thecomputer-implemented method of claim 11, wherein a storage manager thatexecutes on a third computing device is configured to manage one or morestorage policies that define the first amount of time and the secondamount of time, wherein the third computing device is distinct from oneor more of: the client computing device and the first computing device,and wherein the third computing device comprises one or more hardwareprocessors.
 19. The computer-implemented method of claim 11, wherein thefirst drive is configured to execute a first file system and wherein thesecond drive is configured to execute a second file system, which isdistinct from, and of a different type than, the first file system. 20.The computer-implemented method of claim 11, further comprising:receiving an updated version of the first data file; storing the updatedversion of the first data file in the first drive; determining that thefirst data file has changed since a preceding snapshot operation;storing the updated version of the first data file in the second drive,in the native format; and storing, at the first drive, a stub thatreferences the updated version of the first data file stored at thesecond drive.